Question

For Comic Relief Stamford Green School are taking part in a "Bake Off".

Parents are invited to come and buy cakes. 150 parents attend: 70% donate £1 for their cake and the rest donate £2 for their cake. How much money is donated in total?

Answer 1

Start off with %70 of 150

0.7 • 150 = 105

To find their total donation amount,

105 • £1 = £105

Then we know the rest of the parents account for the last %30 of the attendees

We can find this out by either,

150 - 105

or

0.3 • 150

Either way we end up with 45

45 • £2 = £90

%70 (105) of the parents donated £105

%30 (45) of the parents donated £90

The parents, in total, donated £195