Question

Бак наполнится водой через две трубы за 2 часа .через первую трубу бак может наполнится за 3 часа .за сколько времени 2 /3 объема бака наполнится водой через вторую трубу?

Answer 1

1:2 =1/2 бака заполн. через две тр.
1 :3 =1/3 бака заполн. за час через первую
1/2 - 1/3 =1/6 бака за час через вторую
2/3 : 1/6 =4 часа

Answer 2

Problem Analysis

We have a tank that can be filled with water through two pipes. The tank can be filled in 2 hours using both pipes, and it can be filled in 3 hours using the first pipe alone. We need to determine how long it will take to fill 2/3 of the tank using the second pipe alone.

Solution

Let's assume that the capacity of the tank is C liters.

We are given that the tank can be filled in 2 hours using both pipes. This means that the combined rate of filling the tank using both pipes is C/2 liters per hour.

We are also given that the tank can be filled in 3 hours using the first pipe alone. This means that the rate of filling the tank using the first pipe alone is C/3 liters per hour.

To find the rate of filling the tank using the second pipe alone, we subtract the rate of filling using the first pipe alone from the combined rate of filling using both pipes: Rate of filling using the second pipe alone = Combined rate of filling - Rate of filling using the first pipe alone

Let's denote the rate of filling using the second pipe alone as R2.

Therefore, R2 = C/2 - C/3 = (3C - 2C)/(2 * 3) = C/6 liters per hour.

To find the time it takes to fill 2/3 of the tank using the second pipe alone, we divide the volume of 2/3 of the tank by the rate of filling using the second pipe alone: Time = (2/3)C / (C/6) = (2/3) * 6 = 4 hours.

Therefore, it will take 4 hours to fill 2/3 of the tank using the second pipe alone.

Answer

It will take 4 hours to fill 2/3 of the tank with water using the second pipe alone.