Question

30 girls and boys have planned for a picnic there is a ratio of 3 girls to 7 boys how many boys are there

Answer 1

Let the girls be 3x
boys = 7x

total = 7x+3x = 30
⇒ 10x = 30
⇒ x = 30/10
⇒ x = 3
Number of boys = 7*3 = 21