Question

Один рабочий может оклеить обоями помещение за 3 часа. через 20мин работы к нему присоединился второй рабочий, который всю работу может выполнить за 5 часов. за какое время было оклеено все помещение?

Answer 1

Первый рабочий работал 20 минут сам, он оклеил 1/9 комнаты.
8/9 комнаты они клеили вдвоем с суммарной мощностью 2/225 частей комнаты в минуту
8/9:2/225=100минут.+20 минут которые рабочий работал один.
Ответ:120 минут.

Answer 2

Calculating the Time Taken to Wallpaper the Room

To calculate the time taken to wallpaper the room with the two workers, we can use the concept of "work done equals rate multiplied by time."

Let's denote: - W: the fraction of the room that can be wallpapered in one hour by the first worker - T1: the time taken by the first worker alone to wallpaper the entire room - T2: the time taken by the second worker alone to wallpaper the entire room - T: the time taken by both workers together to wallpaper the entire room

We can use the following equation to solve for T: 1/T = 1/T1 + 1/T2

Given: - The first worker can wallpaper the entire room in 3 hours. - The second worker can wallpaper the entire room in 5 hours. - The first worker worked for 20 minutes (1/3 hour) before the second worker joined.

Calculating the Time Taken

Using the equation above, we can calculate the time taken for both workers to wallpaper the entire room.

1/T = 1/3 + 1/5 1/T = 5/15 + 3/15 1/T = 8/15 T = 15/8 T = 1.875 hours

So, the entire room was wallpapered in 1.875 hours when both workers worked together.

This calculation is based on the concept of combined work and the individual rates of the workers.