In a city, 40% of the adults are illiterate while 85% of the children are literate. If the ratio of the adults to that of the children is 2:3, then what percent of the population is literate?

Explanation

Let the number of adults and children be 2x and 3x
` therefore ` Literate population = 60% of 2x + 85% of 3x
` = 15/4 x `
Required % ` = 15/4 x xx (1)/(5x) xx 100% = 75%`