Alan has two spinners, spinner A and spinner B - Edexcel - GCSE Maths - Question 12 - 2017 - Paper 3

Let the total number of spins be represented by $N$.

Given that the number of times both spinners land on red is 24, we can write:

$0.15N = 24$

Solving for $N$ gives:

$N = \frac{24}{0.15} = 160$

The probability that spinner A lands on white is:

$P(A_{white}) = 1 - P(A_{red}) = 1 - 0.25 = 0.75$

The probability that spinner B lands on white is:

$P(B_{white}) = 1 - P(B_{red}) = 1 - 0.6 = 0.4$

Thus, the combined probability of both spinners landing on white is:

$P(A_{white} ext{ and } B_{white}) = P(A_{white}) imes P(B_{white}) = 0.75 imes 0.4 = 0.3$

Using the total number of spins ($N = 160$), the estimated number of times both spinners land on white is:

$0.3N = 0.3 imes 160 = 48$