1. Ratio Word Problems
Example 1:
In a bag of red and green chocolates, the ratio of red chocolates to green chocolates is 3:4. If the bag
contains 120 green chocolates, how many red chocolates are there?
Solution:
Step 1: Assign variables :
Let x = red chocolates
Write the items in the ratio as a fraction.
Step 2: Solve the equation
Cross Multiply
3 × 120 = 4 × x
360 = 4x
Isolate variable x
Answer: There are 90 red chocolates.
Another example on next page
2. Ratio Word Problems
Example 2:
Example 2:
Billy Bob has 30 toys, 18 of which are red and 12 of which are blue. Mary has 20 toys, all of them
either red or blue. If the ratio of the red toys to the blue toys is the same for both Billy Bob and Mary,
then Billy Bob has how many more blue toys than Mary?
Solution:
Step 1: Sentence: Mary has 20 toys, all of them either red or blue.
Assign variables:
Let x = blue toys for Mary
20 – x = red toys for Mary
We get the ratio from Billy Bob
Billy Bob has 30 toys, 18 of which are red and 12 of which are blue.
We use the same ratio for Mary.
Step 2: Solve the equation
Cross Multiply
3 × x = 2 × (20 – x)
3x = 40 – 2x
Isolate variable x
Billy Bob has 12 blue toys. So, he has 12 – 8 = 4 more blue toys than Mary.
Answer: Billy Bob has 4 more blue toys than Mary.