If a class has 158 students, and 1/11 are girls and 1/7 are boys, then how many girls and boys are in the class?

Question

If a class has 158 students, and 1/11 are girls and 1/7 are boys, then how many girls and boys are in the class?

Answer 1

Since this seems to have a problem, here's an example that will work nicely:

 

If a class has 147 students, and 6/14 are girls and 4/7 are boys, then how many girls and boys are in the class?

 

Girls = 6/14 = 3/7 of the class, now multiply the fraction to the number of students

 

(3/7)(147) = (3*147)/7 = (3)(147/7) = (3)(21) = 63

 

So, there are 63 girls in the class. 

 

Now you can either do 147 students - 63 girls = 84 boys

 

or 

 

you can multiply to find boys (like you did for girls)

 

Boys = 4/7

 

(4/7)(147) = (4)(147/7) = (4)(21) = 84

 

Therefore the class has 84 boys and 63 girls. (Note: you would expect that there are more boys than girls because (4/7) > (6/14)

Answer 2

Something is wrong with this problem.

1/11 + 1/7 = 7/77 + 11/77 = 18/77

So, boys and girls combined are 18/77 = approx. 23.4% of the class.

Then what are the other 76.6% who are not boys or girls?