Jack picks a counter at random and then replaces it - OCR - GCSE Maths - Question 7 - 2019 - Paper 5

To find the probability that Jack picks two red counters, we multiply the probabilities of picking a red counter on each pick:

1. For the first pick, the probability of picking a red counter is \frac{4}{7}.
2. For the second pick, after replacing the counter, the probability remains \frac{4}{7}.

Thus, the probability of picking two red counters is:

$P(Red, Red) = P(Red) \times P(Red) = \\frac{4}{7} \times \\frac{4}{7} = \\frac{16}{49}$