Fractions and word problems

Question

 A garden has 1/5 grape tomato plants and 2/9 cherry tomato plants. There are 18 grape tomato plants and 20 cherry tomato plants. How many plants in all?

Answer 1

Let x = the total number of plants in the garden, then translate each part of the problem into math sentences.

 

A garden has 1/5 grape tomato plants...there are 18 grape tomato plants.--> 18=1/5 of x -->18=x/5-->x=18(5)=90

 

Use the second bit of information to check. 2/9 of x should equal 20--> (2/9)(90)=20 ? Yes it does!

 

So there are 90 plants in all.