In a small village of 500 people, 350 speak the local language while 200 speak pidgin English. What percentage of the population speak both.
The correct answer is: B
Explanation

n(L) only = 350 - x
n(P) only = 200 - x
∴350 - x + x + 200 - x = 500
550 - x = 500
x = 550 - 500
x = 50 speak both
∴x% = (50/500) * (100/1)
= 10%