find the fraction which has the same ratio to 1 / 2 that 2 / 5 has to 3 / 7
"a : 1 / 2 = 2 / 5 : 3 / 7 as the product of the means is equal to the product of the extremes . a * 3 / 7 = 1 / 2 * 2 / 5 a * 3 / 7 = 2 / 10 a = 14 / 30 = > a = 14 / 30 answer : c"
multiply(divide(divide(2, 5), divide(3, 7)), divide(1, 2))