A bag contains 1 white and 6 red balls, and a second bag contains 4 white and 3 red balls. One of the bags is picked up at random and a ball is randomly drawn from it, and is found to be white in colour. Find the probability that the drawn ball was from the first bag.

Explanation

To solve the problem step by step, we will use Bayes' theorem.

### Step 1: Define the events
Let:
- \( E_1 \): Event that the first bag is chosen.
- \( E_2 \): Event that the second bag is chosen.
- \( A \): Event that a white ball is drawn.

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