Let x be the number of boys. Then the number of girls is 805-x.
=
4*(805-x) = 3x
4*805 -4x = 3x
4*805 = 3x + 4x
4*805 = 7x
x = = 4*115 = 460.
ANSWER. 460 boys.
CHECK. = = = . ! Correct !
Given that the ratio of girls to boys is 3 to 4, one standard way to start on solving the problem is to let the number of girls be 3x and the number of boys be 4x.
Then, since the total number of students is 805,
The number of boys is 4x = 460.
An even shorter way to use the given ratio of 3 girls to 4 boys is to translate that into saying that 3/7 of the students are girls and 4/7 of them are boys. Then the answer is found with a single simple calculation:
number of boys = (4/7)*805 = 4*(805/7) = 4*115 = 460.