Answer:
1000 boys
Explanation:
The ratio of the number of boys to girls is 4:5.
Every time you multiply 4 and 5 by the same whole number, you get a possible number of boys and girls in the same ratio.
There may be
4 boys and 5 girls, or
8 boys and 10 girls (multiplying 4 and 5 by 2), or
12 boys and 15 girls (multiplying 4 and 5 by 3), or
400 boys and 500 girls (multiplying 4 and 5 by 100),
but all these numbers are too low for there to be a difference of 250 between the numbers of boys and girls. Since we don't know the numbers of boys and girls, but know the ratio is 4:5, then we know that the ratio is also 4x:5x, by multiplying both numbers of boys and girls in the ratio by x.
There are 250 more girls than boys, so
5x - 4x = 250
x = 250
The number of boys is 4x.
4(250) = 1000
Answer: 1000 boys