The ratio of adults to children in a cinema audience is 3:4. There are 84 adults. work out the number of children.
4/3 X 84=112 children
Set it up as a ratio 3/4 = 84/x where 'x' = # children then solve for 'x'
3/4 = 84/x
x = 84 (4/3)
x = 112 children