Question

What is the probability that the product of the numbers is a multiple of 7 ?

Hint:

Instead of checking all 12 products, identify the key condition. A product is a multiple of 7 if at least one factor is a multiple of 7. Only Box 1 contains a multiple of 7 (the number 7 itself). The probability of picking 7 from Box 1 is 1/4. The number from Box 2 doesn't matter (probability is 3/3 = 1). The combined probability is (1)/(4) × 1 = (1)/(4).

Answer 1