math
posted by sridhar .
Henry has $240 more than my cousin Joe, who has $150 more than my friend Ann. Together the
three people have $990. The amount Ann has, in dollars, is:
a. $150 b. $200 c. $390 d. 450 e. $600

H = J + 240
J = 150 + A
H + J + A = 990
Solve those three equations in three unknowns. H, J, and A are the amounts had by Henry, Joe and Ann.
You first step might be to rewrite the last one as
2 J + 240 + A = 990
2 J + A = 750
Then substitute J150 for A and solve for J