Intermediate November 2017 Unit 2 Q7
7. The following cards spell out the name Ystradgynlais.
Y S T R A D G Y N L A I S
In an experiment, the cards are turned face down and rearranged.
A card is selected at random and the letter on the card is recorded.
The experiment is carried out 325 times.
How many times would you expect the letter Y to be recorded? [3]
| Scheme | Marks | Comments |
|---|---|---|
| (Probability of a Y =) \(\dfrac{2}{13}\) or equivalent | B1 | C.A.O. (B1 is implied by an answer of 50.) |
| \(\dfrac{2}{13} \times 325\) | M1 | F.T. ‘their 2/13’, only if <1 AND 2/a or b/13. |
| = 50 | A1 | Must be given as a whole number (truncated or rounded) if following through ‘their fraction’. Allow B1M1A0 for a final answer of 50/325. If no marks awarded SC1 for sight of 25. |