Question

У першій цистерні було 690 л води, а в другій 540л. Цистерни одночасно відкрили. Щохвилини з першої цистерни витікає 25 л. води, а з другої 30л. Через скільки хвилин у другій цистерні залишиться в 1,5 раза менше води, ніж в першій?

Answer 1

объем 1 цистерны=700 л
объем 2 цистерны=540 л
скорость выливания 1ц.=25 л./мин
скорость выливания 2ц.=30 л./мин
пусть х - кол-во минут,потраченных на выливание воды,тогда составим и решим уравнение:
(540-30*х)=(700-25*х):2.5
540-30х=280-10х
540-280=-10х+30х
260=20х
х=13
через 13 мнут

Answer 2

Problem Analysis

We have two tanks, the first one with a capacity of 690 liters and the second one with a capacity of 540 liters. Water is simultaneously flowing out of both tanks at a rate of 25 liters per minute from the first tank and 30 liters per minute from the second tank. We need to determine how many minutes it will take for the second tank to have 1.5 times less water than the first tank.

Solution

To solve this problem, we can set up an equation to represent the amount of water in each tank at any given time. Let's denote the number of minutes that have passed as 't'.

The amount of water remaining in the first tank after 't' minutes can be calculated using the equation: Amount of water in the first tank = Initial amount of water - (Rate of water flow * t)

Similarly, the amount of water remaining in the second tank after 't' minutes can be calculated using the equation: Amount of water in the second tank = Initial amount of water - (Rate of water flow * t)

We are given that the initial amount of water in the first tank is 690 liters and in the second tank is 540 liters. The rate of water flow from the first tank is 25 liters per minute, and from the second tank is 30 liters per minute.

We need to find the value of 't' when the amount of water in the second tank is 1.5 times less than the amount of water in the first tank. Mathematically, this can be represented as: Amount of water in the second tank = 1.5 * Amount of water in the first tank

Let's substitute the given values into the equations and solve for 't'.

Calculation

Amount of water in the first tank after 't' minutes = 690 - (25 * t) Amount of water in the second tank after 't' minutes = 540 - (30 * t)

According to the problem, the amount of water in the second tank is 1.5 times less than the amount of water in the first tank: 540 - (30 * t) = 1.5 * (690 - (25 * t))

Now, we can solve this equation to find the value of 't'.

Solution

Let's simplify the equation: 540 - 30t = 1035 - 37.5t

Combining like terms: 7.5t = 495

Dividing both sides by 7.5: t = 66

Therefore, it will take 66 minutes for the second tank to have 1.5 times less water than the first tank.

Answer

After 66 minutes, the second tank will have 1.5 times less water than the first tank.