The ratio of the number of boys to the number of girls in a tutorial is 2:3. If there are 180 girls, what is the number of boys?
120
Ratio of number of boys to number of girls = 2:3
Number of girls = 180
Let the number of boys be x.
⇒ 23=x180 [∵ they are equivalent ratios]
⇒ 3x=2×180
⇒ x=3603
⇒ x=120
∴ Number of boys are 120.