There are 500 passengers on a train.

7/20 of the passengers are men.

40% of the passengers are women.

the rest of the passengers are children.

work out the number of children on the train?

* show working

In terms of x, find an expression that represents the area of the shaded region. the outer square has side lengths of (x+5) and the inner square has side lengths of (x-2), as shown. area: a1 x + a2 square units submit