Question

Помогите решить задачу!-Старший брат,младший брат, и сестра слепили снеговика за 12 мин.Старший брат может его слепить за 24 мин,младший-за 40 мин. за сколько минут может слепить снеговика сестра? за ранние спасиба!

Answer 1

40-24-12=4...............

Answer 2

Problem Analysis

We are given that the older brother can build a snowman in 24 minutes and the younger brother can build it in 40 minutes. We need to find out how long it will take the sister to build the snowman.

Solution

Let's assume that the sister can build the snowman in x minutes. We can set up the following equation based on the given information:

1/24 (older brother's rate) + 1/40 (younger brother's rate) + 1/x (sister's rate) = 1/12 (combined rate of all three)

To solve for x, we can multiply both sides of the equation by the least common multiple (LCM) of the denominators, which is 120:

5 + 3 + 120/x = 10

Simplifying the equation:

120/x = 2

Cross-multiplying:

2x = 120

Dividing both sides by 2:

x = 60

Therefore, it will take the sister 60 minutes to build the snowman.

Answer

The sister can build the snowman in 60 minutes.