Question

Всего в двух цистернах содержалось 1311 л топлива . Из первой цистерны использовали 1/5 топлива, из второй цистерны использовали 3/8 топлива. Оказалось, что топлива в первой и второй цистернах стало одинаковое количество. Сколько литров топлива было сначала в каждой цистерне?

Answer 1

Ответ:

3+8=11,1+5=6, )=17

1311:11=77

Answer 2

Problem Analysis

We are given that there are two tanks containing a total of 1311 liters of fuel. From the first tank, 1/5 of the fuel is used, and from the second tank, 3/8 of the fuel is used. After using the fuel, it is found that the amount of fuel in both tanks is the same. We need to find the initial amount of fuel in each tank.

Solution

Let's assume that the initial amount of fuel in the first tank is x liters and in the second tank is y liters.

According to the given information, we can set up the following equations:

Equation 1: x + y = 1311 (since the total amount of fuel in both tanks is 1311 liters)

Equation 2: x - (1/5)x = y - (3/8)y (since the amount of fuel in both tanks is the same after usage)

Simplifying Equation 2:

(4/5)x = (5/8)y

Now, we can solve these equations to find the values of x and y.

Solving the Equations

To solve the equations, we can use substitution or elimination method. Let's use the substitution method.

From Equation 1, we have:

x = 1311 - y

Substituting this value of x in Equation 2:

(4/5)(1311 - y) = (5/8)y

Simplifying:

(4/5)(1311) - (4/5)y = (5/8)y

Multiplying through by 40 to eliminate fractions:

32,880 - 32y = 25y

Combining like terms:

57y = 32,880

Dividing both sides by 57:

y = 32,880 / 57

Calculating y:

y ≈ 576.842

Now, substituting this value of y back into Equation 1 to find x:

x = 1311 - y

x = 1311 - 576.842

Calculating x:

x ≈ 734.158

Answer

Therefore, the initial amount of fuel in the first tank was approximately 734.158 liters and in the second tank was approximately 576.842 liters.