Question

The graph shows the percentage of US homes with electricity.

A bar graph where the x axis shows the years 1910, 1920, 1930 and the y axis shows the percentage of homes, from 0 to 90. For all homes: 1910, 10%; 1920, 35%; 1930, 67%. For urban homes: 1910, 10%; 1920, 48%; 1930, 83%.
Between 1910 and 1930, what was the approximate increase in US homes with electricity?

30%
40%
55%
75%

Answer 1

67% − 10% = 57%, which is closest to 55%.