On a school field trip, the school requires that there are 6 teachers for every 90 students. If 135 students attend the trip how many teachers are needed?

Plz help

2 answers

x = teachers are needed.

Proportion:

6 / 90 = x / 135

3 ∙ 2 / 3 ∙ 30 = x / 135

2 / 30 = x / 135

Cross Multiply

2 ∙ 135 = 30 ∙ x

270 = 30 x

Divide both sides by 30

270 / 30 = 30 x / 30

9 = x

x = 9

OR

( 6 / 90 ) ∙ 135 = 6 ∙ 135 / 90 = 810 / 90 = 9
Thanks sm!