In a box of cards, there are only hearts, diamonds, clubs and spades. A card is taken at random from the box. The table shows the probabilities that the card will be a club or will be a spade.
| Suit | Hearts | Diamonds | Clubs | Spades |
|---|---|---|---|---|
| Probability | 0.10 | 0.30 |
The probability that the card will be a heart is five times the probability that it will be a diamond. There are 15 spade cards in the box.
Work out the number of heart cards in the box.
324 exam-style questions on CCEA GCSE Maths Probability. Each one has a worked solution and a mark scheme showing where the marks go.