Awindow-washing crew can wash 10 windows per hour.

how long will it take the crew to complete a building with 200 windows?

a.
20 h

b.
10 h

c.
5 h

d.
2 h

The answer is 20 hours.
If window washing crew can finish 10 windows per hour. Let;s solve how many hours will it take him to finish 200 windows.
=> 200 / 10 = 20 hours,

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.