Question

Двум пекарям надо выло приготовить торт один пекарь может приготовить торт за 10 часов второй за 15 после 4 часов совместной работы первый ушел домой Работу закончил второй За сколько времени был выполнен заказ

Answer 1

Весь торт принимаем за целое :

1) 1 : 10 = 1/10 торта - делает первый пекарь за 1 ч
2) 1 : 15 = 1/15 торта - делает второй за 1 ч
3) 1/10 + 1/15 = 3/30 + 2/30 = 5/30 = 1/6 торта - делают вместе за 1 ч (общая производительность)
4) 1/6 * 4 = 4/6 = 2/3 торта - сделали вместе
5) 1 - 2/3 = 1/3 торта - осталось доделать второму пекарю
6) 1/3 : 1/15 = 1/3 * 15/1 = 15/3 = 5 ч - нужно, чтобы второй доделал заказ.
7) 4 + 5 = 9 ч - сделан заказ ( 4 ч - работали вместе, 5 ч - работал только второй).

Answer 2

4+((1/10+1/15): 1/15)=4+ восемь целых одна третья= 12 целых одна третья

Answer 3

Problem Analysis

Two bakers need to prepare a cake. The first baker can make a cake in 10 hours, and the second baker can make a cake in 15 hours. After working together for 4 hours, the first baker leaves, and the second baker completes the job. We need to determine how long it took to complete the order.

Solution

To solve this problem, we can calculate the combined work rate of the two bakers and then determine the time it takes for the second baker to complete the remaining work.

Let's calculate the combined work rate of the two bakers: - The first baker can make a cake in 10 hours, so their work rate is 1/10 cake per hour. - The second baker can make a cake in 15 hours, so their work rate is 1/15 cake per hour.

After working together for 4 hours, the combined work done by the two bakers is: - The work done by the first baker in 4 hours is 4 * (1/10) = 2/5 of a cake. - The work done by the second baker in 4 hours is 4 * (1/15) = 4/15 of a cake. - The total work done by both bakers in 4 hours is 2/5 + 4/15 = 14/15 of a cake.

Now, let's calculate the remaining work that needs to be done by the second baker: - The total work required to make a cake is 1. - The work done by both bakers in 4 hours is 14/15 of a cake. - Therefore, the remaining work is 1 - (14/15) = 1/15 of a cake.

Since the second baker can make a cake in 15 hours, their work rate is 1/15 cake per hour. Therefore, it will take the second baker 1/15 * 15 = 1 hour to complete the remaining work.

Answer

The order was completed in 1 hour by the second baker after the first baker left.