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.
Practise OCR GCSE Maths Probability with exam-style questions for Foundation and Higher tier. 212 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
