OpenSAT

We can use a Venn diagram to solve this problem. Let the circle representing people who like apples be labeled "A" and the circle representing people who like bananas be labeled "B". The overlap between the two circles represents the people who like both apples and bananas. We know that 20 people like both apples and bananas, so we can fill in the overlap of the circles with 20. Since 60 people like apples in total, we can subtract the 20 who like both apples and bananas to find that 60 - 20 = 40 people like only apples. Since 40 people like bananas in total, we can subtract the 20 who like both apples and bananas to find that 40 - 20 = 20 people like only bananas.