Question

In the United States, the highest incidence of fraternal twin births occurs among Asian-Americans, then African-Americans, then Caucasians. Of every 16200 births, the total number of fraternal twin births for all three is 778, where there are 195 more for Asian-Americans than African-Americans and 242 more for Asian-Americans than Caucasians. Determine the number for each race.

Out of every 16200 births, there are_____? sets of Asian-American twins,_____? sets of African-American twins, and _____? sets of Caucasian twins.

Answer 1

as + af + ca = 778
af = as -195
ca = as -242
so
as + as-195 + as-242 = 778

3 as = 1215
as = 405

you can take it from there I think.

Answer 2

I got 405, 210, and 163.

Answer 3

Good.