Higher June 2023 Paper 2R Q15
15 Osvaldo has a biased coin.
He spins the coin three times.
The probability that the coin lands on a head three times is \(\dfrac{27}{64}\)
Work out the probability that the coin will land on a tail three times.
(3)
| Scheme | Marks |
|---|---|
| \(\sqrt[3]{\dfrac{27}{64}}\left(= \dfrac{3}{4} = 0.75\right)\) | M1 |
| \(\left(1 - \text{``}\dfrac{3}{4}\text{''}\right)^3\) or \(\left(\dfrac{1}{4}\right)^3\) or \(0.25^3\) | M1 |
Correct answer scores full marks (unless from obvious incorrect working) Answer: \(\dfrac{1}{64}\) | A1 |
| (3) | |
| (3 marks) |
Notes
M1: for finding the probability of a head
M1: for a complete method
A1: oe
Accept 0.015(625) or 1.55(625)% truncated or rounded