Question

Шесть насосов выкачивают всю воду из бассейна за 10 часов. а) Сколько надо таких же насосов, чтобы выкачать вод у из этого бассейна за 5 ч? за 15 ч? б) За какое время выкачают всю воду из этого бассейна 3 таких же насоса? 9 таких же насосов?

Answer 1

За 1 час 6 насосов выкачивают 1/10 часть бассейна. Значит, 1 насос за 1 час выкачивает 1/60 часть.
а) За 5 ч 1 насос выкачает 5/60=1/12 часть, а 12 насосов - весь бассейн.
За 15 ч 1 насос выкачает 15/60=1/4 часть, а 4 насоса - весь бассейн.
б) 3 насоса за 1 час выкачают 3/60=1/20 часть, а весь бассейн за 20 часов.
9 насосов за 1 час выкачают 9/60=3/20 часть, а весь бассейн за 20/3 = 6 2/3 часа = 6 ч 40 мин

Answer 2

Question Analysis

The question asks for detailed calculations regarding the number of pumps needed to drain a pool in different time frames and the time it would take for a certain number of pumps to drain the pool.

Answer

a) To calculate the number of pumps needed to drain the pool in 5 hours and 15 hours, we can use the information given: 6 pumps can drain the entire pool in 10 hours.

- To drain the pool in 5 hours, we need to double the number of pumps. Therefore, we would need 12 pumps. - To drain the pool in 15 hours, we can calculate the number of pumps needed by dividing the time by the original time and multiplying it by the original number of pumps. Therefore, we would need 18 pumps.

b) To calculate the time it would take for 3 pumps and 9 pumps to drain the entire pool, we can use the information given: 6 pumps can drain the entire pool in 10 hours.

- To drain the pool with 3 pumps, we can calculate the time by dividing the original number of pumps by the desired number of pumps and multiplying it by the original time. Therefore, it would take 20 hours. - To drain the pool with 9 pumps, we can calculate the time by dividing the original number of pumps by the desired number of pumps and multiplying it by the original time. Therefore, it would take 3.33 hours (approximately).

Please note that these calculations assume that the pumps work at a constant rate and there are no other factors affecting the draining process.