WAEC Mathematics 2011 Paper

Concept:Students who like both dancing and swimming are counted in the overlap of the dancing and swimming circles.Explanation:From the Venn diagram, the total number of students who like swimming is $16$.The parts inside the swimming circle are $6$, $3$, $2$, and $x$.Let $x$ be the number of students who like dancing and swimming only.The number $2$ represents students who like reading, dancing, and swimming.So, the swimming total is $6 + 3 + 2 + x = 16$.This simplifies to $11 + x = 16$.Hence, $x = 16 - 11 = 5$.The number of students who like dancing and swimming is $x + 2 = 5 + 2 = 7$.Answer:$7$Option A.