Question

On a boat ride tour there are half as many children as there are adults. There are 30 people on the tour. How many children are there

Answer 1

Total number of people on boat=30
Half as many children as adults means:
Number of children = 1/2 ( Adults)
Let number of adults= A
Then equation is:
$A+ \frac{1}{2}A = 30 \\ Multiply \ both \ sides \ by \ 2. \\ 2A+A=60 \\ 3A=60 \\ A=20$ 
So number of children= 1/2 x 20 =10

Answer: 10 Children