Foundation June 2021 Paper 2 Q13
13 There are some counters in a bag.
7 of the counters are blue.
5 of the counters are green.
The rest of the counters are yellow.
One counter is going to be taken at random from the bag.
The probability that the counter is blue or is green is \(\dfrac{6}{13}\)
Work out how many yellow counters there are in the bag.
(3)
| Scheme | Marks |
|---|---|
eg 7 + 5 = 12 and \(\dfrac{6}{13} = \dfrac{12}{26}\) or 26 or eg \(\dfrac{7 + 5}{7 + 5 + x} = \dfrac{6}{13}\) and \(13(7 + 5) = 6(7 + 5 + x)\) | M1 |
| eg 26 – 12 or eg \(6x = 84\) | M1 |
| Working not required, so correct answer scores full marks (unless from obvious incorrect working) Answer: 14 | A1 |
| (3) | |
| (3 marks) |
Notes
M1: for method to find the total number of counters
M1: complete method to find the number of yellow counters
or
a correct equation with \(x\) terms isolated
A1: cao