The number of girls in Shana's class is 2 more than the number of boys. Four times the number of boys is seven more than three times the number of girls. How many girls are in Shana's class?

A) 9
B) 11
C) 13
D) 15

Question

The number of girls in Shana's class is 2 more than the number of boys. Four times the number of boys is seven more than three times the number of girls. How many girls are in Shana's class?

A) 9
B) 11
C) 13
D) 15

anonymous · Answer

g=2+b                      4b=7+3g    2 equations
we can substitute the value of g

4b=7+3g
4b= 7+ 3(2+b)
4b=7+6+3b
4b-3b=13
b=13    

g=2+b
g=2+13
g=15

anonymous · Answer

This is fantastic! This helps a lot, and this showed us the process for some other problems. Thank you~