Cov txheej txheem:

12 Cov teeb meem Soviet uas tsuas yog cov ntse tshaj tuaj yeem daws tau
12 Cov teeb meem Soviet uas tsuas yog cov ntse tshaj tuaj yeem daws tau
Anonim

Ntsuam xyuas koj cov kev txawj ntse!

12 Cov teeb meem Soviet uas tsuas yog cov ntse tshaj tuaj yeem daws tau
12 Cov teeb meem Soviet uas tsuas yog cov ntse tshaj tuaj yeem daws tau

1. Yuav faib li cas?

Ob tug phooj ywg noj porridge: ib tug ncuav 200 g ntawm cereal rau hauv lub lauj kaub, lwm yam - 300 g. Thaum lub porridge npaj txhij thiab cov phooj ywg tab tom noj nws, ib tug passer-by-los koom lawv thiab koom noj mov nrog lawv. Tawm mus, nws tso lawv 50 kopecks rau nws. Cov phooj ywg yuav tsum faib cov nyiaj uas lawv tau txais li cas?

Feem coob ntawm cov neeg uas daws qhov teeb meem no teb hais tias tus uas ncuav 200 g ntawm cereal yuav tsum tau 20 kopecks, thiab tus uas ncuav 300 g - 30 kopecks. Xws li ib tug faib yog kiag li unfounded.

Peb yuav tsum xav li no: 50 kopecks tau them rau feem ntawm ib tus neeg noj. Txij li thaum muaj peb tus neeg noj, tus nqi ntawm tag nrho cov porridge (500 g) yog sib npaug rau 1 ruble 50 kopecks. Ib tug uas nchuav 200 g ntawm cereal pab 60 kopecks nyob rau hauv cov nyiaj (vim 100 g nqi 150 ÷ 500 × 100 = 30 kopecks). Nws noj 50 kopecks, uas txhais tau tias nws yuav tsum tau muab 60 - 50 = 10 kopecks. Tus neeg uas tau pab 300 g (uas yog, 90 kopecks hauv cov nyiaj) yuav tsum tau txais 90 - 50 = 40 kopecks.

Yog li, ntawm 50 kopecks, ib tug yuav tsum noj 10, thiab lwm yam 40.

Qhia teb Nthuav teb

2. Phau ntawv nqe

Ivanov yuav tag nrho cov ntaub ntawv nws xav tau los ntawm ib tug neeg muag ntawv uas nws paub nrog 20% luv nqi. Txij Lub Ib Hlis 1, cov nqi ntawm txhua phau ntawv tau nce 20%. Ivanov txiav txim siab tias tam sim no nws yuav them rau cov phau ntawv ntau npaum li tus so ntawm cov neeg yuav khoom them ua ntej Lub Ib Hlis 1. Nws puas yog?

Ivanov tam sim no yuav them tsawg dua li cov neeg yuav khoom them ua ntej Lub Ib Hlis 1. Nws muaj 20% luv nqi ntawm tus nqi nce 20% - nyob rau hauv lwm yam lus, 20% luv nqi ntawm 120%. Ntawd yog, nws yuav them rau phau ntawv tsis yog 100%, tab sis tsuas yog 96% ntawm nws tus nqi dhau los.

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3. Qaib thiab qaib qe

Cov pob tawb muaj qe, qee cov qe qaib thiab lwm cov qe qaib. Tus lej ntawm cov qe yog 5, 6, 12, 14, 23, 29. "Yog tias kuv muag lub pob tawb no," tus tub lag luam xav tias, "Kuv yuav muaj ob npaug ntau dua li cov qe qaib li cov qe qaib." Nws txhais li cas pob tawb?

Tus neeg muag khoom tau xa mus rau ib pob tawb ntawm 29 qe. Cov qaib nyob hauv pob tawb 23, 12, thiab 5; duck - hauv pob tawb, suav nrog 14 thiab 6 daim. Cia peb kuaj. Muaj 23 + 12 + 5 = 40 qaib qe tag nrho. Cov qe qaib - 14 + 6 = 20. Muaj ob zaug qaib qe ntau li cov qe qaib, raws li qhov xav tau ntawm qhov teeb meem ntawm qhov teeb meem.

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4. Cov thoob

6 lub thoob ntawm kerosene raug xa mus rau lub khw. Daim duab qhia tias muaj pes tsawg lub thoob ntawm cov kua no nyob hauv txhua lub thoob. Thawj hnub, ob tus neeg yuav khoom tau pom; ib tug yuav 2 lub thoob nkaus, lwm tus - 3, thiab thawj tus neeg yuav ib nrab li ntau npaum li cas kerosene li tus thib ob. Yog li ntawd kuv tsis txawm yuav tsum tau uncork lub chim. Ntawm 6 lub thawv, tsuas yog ib qho tseem nyob hauv lub warehouse. Qhov twg?

teeb meem lej: kerosene chim
teeb meem lej: kerosene chim

Thawj tus neeg yuav khoom 15- thoob thiab 18- thoob thoob. Qhov thib ob muaj 16 thoob, 19 thoob thiab 31 thoob. Xwb: 15 + 18 = 33, 16 + 19 + 31 = 66, uas yog, tus neeg thib ob muaj ob npaug ntau dua li cov roj ntsha li thawj. Ib lub thoob 20 lub thoob tseem tsis tau muag. Qhov no yog qhov kev xaiv nkaus xwb. Lwm qhov sib xyaw ua ke tsis muab qhov xav tau piv.

Qhia teb Nthuav teb

5. lab khoom

Cov khoom muaj qhov hnyav ntawm 89.4 g. Xav txog hauv koj lub siab ntau npaum li cas ib lab cov khoom hnyav.

Koj yuav tsum xub muab 89.4 g ib lab, uas yog, los ntawm ib txhiab txhiab. Peb muab faib ua ob kauj ruam: 89.4 g × 1,000 = 89.4 kg, vim hais tias ib kilogram yog ib txhiab npaug tshaj ib gram. Ntxiv: 89.4 kg × 1,000 = 89.4 tons, vim hais tias ib tug ton yog ib txhiab npaug tshaj ib kilogram. Qhov hnyav yuav tsum yog 89.4 tons.

Qhia teb Nthuav teb

6. yawg thiab tub xeeb ntxwv

- Qhov kuv yuav hais tau tshwm sim xyoo 1932. Thaum ntawd kuv twb laus npaum li ob tus lej kawg ntawm lub xyoo uas kuv yug los. Thaum kuv hais rau kuv yawm txiv txog qhov piv txwv no, nws ua rau kuv xav tsis thoob nrog cov lus hais tias tib yam tshwm sim nrog nws hnub nyoog. Nws zoo li kuv ua tsis tau …

"Impossible, tau kawg," ib lub suab interjected.

- Xav txog, nws yog qhov ua tau. Kuv yawm txiv ua pov thawj rau kuv. Peb txhua tus muaj pes tsawg xyoo?

Thaum xub thawj siab ib muag, tej zaum nws yuav zoo nkaus li tias qhov teeb meem tsis raug tsim: nws hloov tawm tias tus tub xeeb ntxwv thiab yawg yog tib lub hnub nyoog. Txawm li cas los xij, qhov xav tau ntawm qhov teeb meem, raws li peb tam sim no yuav pom, yooj yim txaus siab.

Tus tub xeeb ntxwv tau tshwm sim hauv xyoo pua 20th. Thawj ob tus lej ntawm lub xyoo yug, yog li ntawd, 19. Tus lej qhia los ntawm tus lej seem, thaum ntxiv rau nws tus kheej, yuav tsum yog 32. Qhov no txhais tau tias tus lej no yog 16: xyoo yug ntawm tus tub xeeb ntxwv yog. Xyoo 1916, thiab nws muaj hnub nyoog 16 xyoo hauv xyoo 1932.

Nws yawg tau yug los, tau kawg, nyob rau xyoo 19th; thawj ob tus lej ntawm nws lub xyoo yug - 18. Tus lej ob npaug qhia los ntawm tus lej seem yuav tsum yog 132. Qhov no txhais tau tias tus lej no nws tus kheej sib npaug rau ib nrab 132, uas yog, 66. Yawg yug xyoo 1866, thiab xyoo 1932 nws muaj 66 xyoo.

Yog li ntawd, ob tus tub xeeb ntxwv thiab yawg nyob rau xyoo 1932 tau muaj hnub nyoog li ob tus lej kawg ntawm lub xyoo yug ntawm lawv txhua tus qhia.

Qhia teb Nthuav teb

7. Cov nqi tsis hloov pauv

Ib tug poj niam muaj ntau daim nqi nyiaj hauv nws lub hnab nyiaj. Nws tsis muaj lwm yam nyiaj nrog nws.

  1. Tus poj niam siv nyiaj ib nrab ntawm kev yuav lub kaus mom tshiab, thiab them $ 1 rau haus dej haus tshiab.
  2. Mus rau tom khw noj tshais, tus poj niam siv ib nrab ntawm nws cov nyiaj seem thiab them ntxiv $ 2 rau luam yeeb.
  3. Nrog ib nrab ntawm cov nyiaj tshuav tom qab ntawd, nws yuav ib phau ntawv, ces thaum txoj kev mus tsev nws mus rau ib qho bar thiab xaj ib qho cocktail rau $ 3. Yog li ntawd, $ 1 tseem nyob.

Tus poj niam muaj pes tsawg las thaum xub thawj, yog peb xav tias nws yeej tsis tau hloov cov nqi uas twb muaj lawm?

Cia peb pib daws qhov teeb meem los ntawm qhov kawg, uas yog, los ntawm lub ntsiab lus thib peb. Ua ntej yuav ib lub cocktail, tus poj niam muaj 1 + 3 = 4 las. Yog tias nws yuav phau ntawv rau ib nrab ntawm cov nyiaj tshuav, ces ua ntej yuav phau ntawv nws muaj 4 × 2 = 8 las.

Cia peb mus taw tes 2. Tus poj niam them $2 rau cov luam yeeb, yog tias ua ntej yuav lawv, nws muaj 8 + 2 = 10 las. Ua ntej yuav luam yeeb, tus poj niam siv ib nrab ntawm cov nyiaj muaj nyob rau lub sijhawm ntawd rau noj tshais. Yog li ntawd, ua ntej noj tshais, nws muaj 10x2 = $ 20.

Cia peb txav mus rau thawj qhov chaw. Tus poj niam them 1 duas las rau haus dej haus: 20 + 1 = 21. Qhov no txhais tau tias ua ntej yuav lub kaus mom nws muaj 21 × 2 = 42 las.

Qhia teb Nthuav teb

8. Peb tus neeg ua haujlwm khawb ib qhov kwj dej

Peb tus neeg ua haujlwm tau khawb ib qhov kwj dej. Thaum xub thawj, thawj ntawm lawv tau ua haujlwm ib nrab ntawm lub sijhawm nws siv rau ob leeg txhawm rau khawb tag nrho cov kwj dej. Ces tus txiv neej thib ob ua hauj lwm ib nrab ntawm lub sij hawm nws coj ob tug mus khawb tag nrho kwj dej. Thaum kawg, tus neeg koom thib peb tau ua haujlwm ib nrab ntawm lub sijhawm nws siv rau ob leeg txhawm rau khawb tag nrho cov kwj dej.

Raws li qhov tshwm sim, kev ua haujlwm tau ua tiav tag nrho, thiab 8 teev dhau los txij li thaum pib ntawm cov txheej txheem. Nws yuav siv sijhawm ntev npaum li cas peb tus neeg khawb av khawb qhov kwj dej no, ua haujlwm ua ke?

Cia ob leeg ua hauj lwm ib txhij nrog thawj tus neeg koom. Raws li qhov xwm txheej, thaum lub sijhawm ua haujlwm ntawm thawj zaug, ob qho tib si yuav khawb ib nrab ntawm kwj dej. Nyob rau hauv tib txoj kev, thaum lub thib ob ua hauj lwm, thawj thiab thib peb yuav khawb ntau ib nrab-trenches, thiab thaum lub thib peb ua hauj lwm, ib nrab-trenches yuav muab thawj thiab thib ob. Qhov no txhais tau hais tias nyob rau hauv 8 teev tag nrho ua ke lawv yuav tau khawb ib tug kwj thiab ib tug thiab ib nrab kwj, tag nrho ntawm 2, 5 kwj. Thiab peb ntawm lawv yuav khawb ib lub qhov hauv 8 ÷ 2, 5 = 3, 2 teev.

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9. African tsej

Muaj 800 tus poj niam ntawm cov pejxeem ntawm ib lub zos African. Peb feem pua ntawm lawv hnav ib lub qhwv ntsej txhua, ib nrab ntawm cov neeg nyob hauv, ib nrab ntawm cov neeg nyob hauv, uas tshuav 97%, hnav ob lub qhwv ntsej, thiab ib nrab tsis hnav qhwv ntsej txhua. Muaj pes tsawg qhwv ntsej tuaj yeem suav rau hauv pob ntseg ntawm tag nrho cov poj niam pej xeem ntawm lub zos? Qhov teeb meem yuav tsum tau daws nyob rau hauv lub siab, tsis muaj resorting rau improvised computational cuab yeej.

Yog tias ib nrab ntawm 97% ntawm cov neeg zej zog hnav ob lub tsej, thiab ib nrab tsis hnav lawv ib nrab, ces tus naj npawb ntawm qhwv ntsej rau ib feem ntawm cov pejxeem no yog tib yam li cov poj niam hauv zos tau hnav ib pob ntseg.

Yog li ntawd, thaum txiav txim siab tag nrho cov qhwv ntsej, peb tuaj yeem xav tias txhua tus neeg nyob hauv lub zos hnav ib lub qhwv ntsej, thiab txij li 800 tus poj niam nyob ntawd, ces muaj 800 qhwv ntsej.

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10. Tus thawj taug kev

Rau ib tus thawj coj, uas nyob hauv nws lub dacha, lub tsheb tuaj thaum sawv ntxov thiab coj nws mus ua haujlwm ntawm ib lub sijhawm. Thaum tus thawj coj no, txiav txim siab taug kev, tawm 1 teev ua ntej lub tsheb tuaj txog thiab taug kev ntawm nws. Ntawm txoj kev, nws tau ntsib ib lub tsheb thiab tuaj txog ntawm chaw ua haujlwm 20 feeb ua ntej nws pib. Txoj kev taug kev mus ntev npaum li cas?

Txij li thaum lub tsheb tsuas yog "yeej" 20 feeb, ces qhov kev ncua deb ntawm qhov chaw uas nws tau ntsib tus thawj, mus rau nws dacha thiab rov qab, nws yuav tau them nyob rau hauv 20 feeb. Qhov no txhais tau hais tias tus neeg tsav tsheb muaj 10 feeb ua ntej lub dacha, thiab txij li thaum tus neeg caij tsheb tawm hauv tsev ib teev ua ntej lub tsheb tuaj txog, kev taug kev mus txog 60 - 10 = 50 feeb.

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11. Cov tsheb ciav hlau tuaj

Ob tug neeg caij tsheb ciav hlau, ob qho tib si ntev 250 m, mus rau ib leeg ntawm tib qhov ceev ntawm 45 km / h. Muaj pes tsawg lub vib nas this yuav dhau mus tom qab cov neeg tsav tsheb sib ntsib ua ntej cov neeg sib tw ntawm cov tsheb thauj neeg kawg tau ntsib?

Thaum lub sij hawm cov neeg tsav tsheb sib ntsib, qhov kev ncua deb ntawm cov conductors yuav yog 250 + 250 = 500 m. Txij li thaum txhua lub tsheb ciav hlau mus ntawm ib tug ceev ntawm 45 km / h, cov conductors mus txog ib tug ceev ntawm 45 + 45 = 90 km /. h, los yog 25 m / s. Lub sijhawm xav tau yog 500 ÷ 25 = 20 s.

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12. Muaj pes tsawg xyoo?

Xav tias koj yog tus tsav tsheb tavxij. Koj lub tsheb tau pleev xim daj thiab dub thiab koj tau tsav nws tau 10 xyoo. Lub bumper ntawm lub tsheb yog phem heev, lub carburetor thiab cua txias yog qua ntxi. Lub tank tuav 60 litres roj av, tab sis tam sim no tsuas yog ib nrab puv. Lub roj teeb yuav tsum tau hloov pauv: nws tsis ua haujlwm zoo. Tus tsav tsheb tavxij muaj pes tsawg xyoo?

Txij thaum pib, qhov teeb meem hais tias koj yog tus tsav tsheb tavxij. Qhov no txhais tau hais tias tus tsav tsheb muaj hnub nyoog li koj.

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Phau ntawv "Legendary Soviet Problems in Mathematics, Physics thiab Astronomy" los ntawm I. Gusev thiab A. Yadlovsky
Phau ntawv "Legendary Soviet Problems in Mathematics, Physics thiab Astronomy" los ntawm I. Gusev thiab A. Yadlovsky

Qhov kev xaiv no yog raws li cov ntaub ntawv los ntawm phau ntawv "" los ntawm I. Gusev thiab A. Yadlovsky. Nyob rau hauv nws koj tuaj yeem nrhiav qhov zoo tshaj plaws puzzles, yam tsis muaj uas tsis yog ib qho kev tshawb fawb thiab kev kawm ntawv ntawm Soviet Union yuav ua tau ib zaug.

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