In a bag there are only red counters, blue counters, green counters and pink counters - Edexcel - GCSE Maths - Question 7 - 2021 - Paper 3

To complete the table, we first denote the probability of taking a green counter as $P(g)$ and the probability of taking a pink counter as $P(p)$.

From the information given, we know:

1. $P(g) = P(p) + 0.2$.
2. The sum of all probabilities should equal 1: $P(r) + P(b) + P(g) + P(p) = 1$ Where:
   • $P(r) = 0.05$ (red)
   • $P(b) = 0.15$ (blue)
   • Thus, $0.05 + 0.15 + P(g) + P(p) = 1$ $P(g) + P(p) = 0.8$

Substituting $P(g)$: $P(p) + 0.2 + P(p) = 0.8$ $2P(p) + 0.2 = 0.8$ $2P(p) = 0.8 - 0.2 = 0.6$ $P(p) = 0.3$

Thus, substituting back, we find: $P(g) = 0.3 + 0.2 = 0.5$

The completed table is:

Colour	red	blue	green	pink
Probability	0.05	0.15	0.5	0.3