In the figure given below, the three circles show the members of a fitness club who do yoga, running and swimming; each number is the number of members in that region.
How many members do at least two of the three activities?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 21
‘At least two’ means two or three activities, so every region shared by two circles is counted, and the region shared by all three circles as well.
Yoga and running only: 6
Yoga and swimming only: 4
Running and swimming only: 8
All three activities: 3
Total \(=6+4+8+3=21\)
Checking the other options
Option (2): 18 — Incorrect. This counts only exactly two activities and leaves out the 3 in the centre, who do all three.
Option (3): 32 — Incorrect. This is the number who do exactly one activity.
Option (4): 53 — Incorrect. This is the number of members in all the regions together.