WAEC 2021 · Paper 2 · Q1

1. Draw three overlapping circles M, P and C.
2. Nobody applied for both Mathematics and Chemistry, so the regions M and C only and all three are empty.
3. The 2 who applied for Mathematics and Physics are therefore M and P only.
4. Let $x$ be Physics and Chemistry only, $y$ Physics only and $a$ Chemistry only.
5. Physics: $2 + x + y = 5$, so $x + y = 3$.
6. Chemistry: $x + a = 3$.
7. All 10 applicants are in the diagram: $3 + 2 + x + y + a = 10$, so $x + y + a = 5$.
8. Since $x + y = 3$, $a = 2$.

(a)

1. From $x + a = 3$: $x = 1$.
2. One person applied for Physics and Chemistry only.

(b)

1. Chemistry only: $a = 2$.