n(T ∪ C) = 1,500, n(T) = 950, n(C) = 700
Using n(T ∪ C) = n(T) + n(C) - n(T ∩ C)
1,500 = 950 + 700 - n(T ∩ C)
1,500 = 1,650 - n(T ∩ C)
n(T ∩ C) = 1,650 - 1,500 = 150
n(T ∩ C) = 150
Number of people who can drink tea only
= n(H ∩ E1) = n(H) - n(H ∩ E)
= 950 - 150 = 800