Foundation June 2019 Paper 2 Q16
16 Four biased coins, A, B, C and D are thrown.
The probability that each coin will land on Heads is shown in the table.
| Coin | Probability |
|---|---|
| A | 0.33 |
| B | 0.033 |
| C | \(\dfrac{1}{3}\) |
| D | 30% |
(a)
(i) Which coin is least likely to land on Heads? (1)
(ii) Which coin is most likely to land on Heads? (1)
Julie says,
“The probability that coin C will land on Heads is the same as the probability that coin C will land on Tails.”
(b) Is she correct?
Give a reason for your answer. (1)
Give a reason for your answer. (1)
Coin B is going to be thrown 4000 times.
(c) Work out an estimate for the number of times coin B will land on Heads. (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| B | B1 | for B, accept 0.033 on the answer line |
| Answer | Mark | Mark scheme |
|---|---|---|
| C | B1 | for C, accept \(\frac{1}{3}\) on the answer line |
| Answer | Mark | Mark scheme |
|---|---|---|
| Statement | C1 | eg No with \(\left(\frac{1}{3}\right)\) and \(\frac{2}{3}\) or No, probabilities would need to be \(\frac{1}{2}\) or No since \(\frac{1}{3} + \frac{1}{3}\) does not equal 1 or No since tails is 67% (or 0.67) |
Additional guidance
Accept rounded conversions seen to decimals or percentages if the reasoning is correct
| Answer | Mark | Mark scheme |
|---|---|---|
| 132 | M1 | for \(4000 \times 0.033\) OR \(\dfrac{132}{4000}\) |
| A1 | cao |
Additional guidance
132 out of 4000 is an acceptable answer