Identify boys and girls in a group

Question

A group of 30 children were given a number of lollipops. Each boy was given 4 lollipops and each girl 5. The girls had 33 more lollipops than the boys. How many girls were there in the group?

Answer 1

b + g = 30     {equation 1}

4b = 5g - 33   {equation 2}

 

g = 30-b ... from equation 1

substitute into equation 2

4b = 5(30-b)-33

4b = 150-5b-33

9b = 117

b = 13 boys

 

13 boys, 17 girls