Question

Чебуреки может разгрузить машинка апельсинов за 6 часов , а крокодил Гена - за 4 часа. Чебарашка поработал 2 часа, а затем ему на помощь пришёл Гена. За сколько часов они разгрузили машину?

Answer 1

1/6 часть - разгружает Чебурашка за  1 ч
1/4 часть - Гена за 1 час

1/6*2=1/3 часть - сделал Ч за 2 часа
1 - 1/3=2/3 части - осталось разгрузить
1/6+1/4=2/12+3/12=5/12(частей) - делают за 1 час вместе
2/3 : 5/12=2/3*12/5=8/5=1 3/5(ч) - разгружали вместе
1 3/5+2=3 3/5(ч) - всего разгружали машину

Answer 2

Problem Setup

Let's solve the problem step by step. We have the following information: - The time it takes for Cheburashka to unload the oranges is 6 hours. - The time it takes for Gena the Crocodile to unload the oranges is 4 hours. - Cheburashka worked for 2 hours before Gena joined to help.

Solution

To find out how long it takes for both Cheburashka and Gena to unload the oranges together, we can use the formula: \[ \frac{1}{t_{\text{combined}}} = \frac{1}{t_{\text{Cheburashka}}} + \frac{1}{t_{\text{Gena}}} \] where: - \(t_{\text{combined}}\) is the time taken when working together. - \(t_{\text{Cheburashka}}\) is the time taken by Cheburashka alone. - \(t_{\text{Gena}}\) is the time taken by Gena alone.

Plugging in the given values: \[ \frac{1}{t_{\text{combined}}} = \frac{1}{6} + \frac{1}{4} \]

Solving for \(t_{\text{combined}}\): \[ \frac{1}{t_{\text{combined}}} = \frac{2}{12} + \frac{3}{12} = \frac{5}{12} \] \[ t_{\text{combined}} = \frac{12}{5} = 2.4 \text{ hours} \]

Answer

So, Cheburashka and Gena together will unload the oranges in 2.4 hours.