Verified Answer :

NerdT10

You have to divide 400 by 5. That will equal 80. Since the ratio is 3:2 Just multiply 3 by 80 then 2 by 80! :-) 

You can check it by simplifying it again.

240 people are boys 
1.You have to find the total of boys and girls there are by adding 3 with 2. (5)
2. You have to divide 400 by 5. (80)
3. You have to multiply 80 by 3 to get the amount of boys there are in 400 people. (240)