One window washer can wash 30 windows in 2 hours. At this rate, how many windows can be washed in 8 hours by 3 window washers?

1 washer ---- 30 windows ----- 2 hours

3 washers ---- 90 windows ---- 2 hours **
3 washers ----360 windows ---- 8 hours ***

** , used only this part
1 washer ---- 30 windows
3 washers ---- 90 windows

***, used only this part
90 windows ---- 2 hours
360 windows ---- 8 hours

isnt it 720 windows

no

in the last part, the time quadrupled, so the number of window would also quadruple.
2 hrs times 4 = 8 hrs
90 windows times 4 = 360 windows

how did you get 720 ?

To determine the number of windows that can be washed in 8 hours by 3 window washers, we need to calculate the rate at which each window washer works.

Given that one window washer can wash 30 windows in 2 hours, we can calculate their rate per hour.

Rate per hour = Number of windows washed / Number of hours

Rate per hour of one window washer = 30 windows / 2 hours = 15 windows per hour

Now, to calculate the total number of windows washed by 3 window washers in 8 hours, we multiply the rate per hour of one window washer by the number of window washers and the number of hours.

Total number of windows washed = Rate per hour * Number of window washers * Number of hours
= 15 windows/hour * 3 window washers * 8 hours
= 360 windows

Therefore, 3 window washers can wash 360 windows in 8 hours.