Question 358183
one painter can paint 2 rooms in 90 minutes. if there are 50 rooms how many
painters are needed to paint all rooms in 7.5 hours.
<pre>
1 painter's rate = {{{(2rooms)/(1.5hours)}}}{{{""=""}}}{{{2/1.5=20/15=4/3}}}rooms/hour

n painters' combined rate = {{{4/3}}}n  rooms/hour

rooms = rate * time

   50 = {{{4/3}}}n * 7.5

Multiply through by 3

 150 = 4n*7.5

 150 = 30n

   5 = n

It would take 5 painters.

Edwin</pre>