Question

Один кран наполняет ванную за 15 мин. а второй за 20 мин. За сколько они вместе наполнят ванну?

Answer 1

Решение:
Обозначим объём ванной за 1(единицу) , то один кран в минуту заполняет:
1:15=1/15 части ванны, а другой кран 1:20=1/20 части ванны
Если краны будут оба заполнять ванну, то они заполнят её за:
1:(1/15+1/20)=1:(4/60+3/60)=1:7\60=60/7 =8  4/7 мин

Ответ: 8 4/7 мин

Answer 2

15+20=35(мин.)
Ответ: за 35 мин. они вместе наполнят ванну.

Answer 3

Calculation of Bathtub Filling Time

To find out how long it will take for both taps to fill the bathtub together, we can use the concept of "work done" or "rate of work" to calculate the combined filling time.

- The first tap fills the bathtub in 15 minutes. - The second tap fills the bathtub in 20 minutes.

To calculate the combined filling time, we can use the formula: Combined Filling Time = (Time taken by Tap 1 * Time taken by Tap 2) / (Time taken by Tap 1 + Time taken by Tap 2)

Calculation

Using the formula: Combined Filling Time = (15 * 20) / (15 + 20)

Result

The combined filling time for both taps to fill the bathtub together is 9 minutes and 26.67 seconds.

This calculation is based on the individual filling rates of the taps and assumes that both taps are working simultaneously and at a constant rate.