Baby boom
Which of the cities shown had the largest percentage increase in population?
Age
14 to 16
Challenge level
Problem
The populations of five cities A, B, C, D, E, in 1998 and 1988, are shown on these scales.
Image
Which of the five cities showed the largest percentage increase in population from 1988 to 1998?
Student Solutions
Answer: C
Population in thousands
A. $40$ to $50$ is an increase of $\frac{10}{40}=25\%$
B. $50$ to $70$ is an increase of $\frac{20}{50}=40\%$
C. $70$ to $100$ is an increase of $\frac{30}{70}=42{6\over7}\%$
D. $100$ to $130$ is an increase of $30\%$
E. $120$ to $160$ is an increase of $\frac{40}{120} =33{1\over3}\%$