Problema Solution

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

Answer provided by our tutors

Let the no. fraternal twin births for caucasians be x.

Then, No. of asian americans=242+x

No. of african-americans=242+x-195

Now,

x+242+x+242+x-195=778

or, 3x+484-195=778

or, 3x+289=778

or, 3x=778-289

or, x=489/3

or, x=163

Therefore,

No. of caucasians=163

African-americans=163+49=210

Asian-americans=242+163=405