Answer:
32
Step-by-step explanation:
let b represent the number of blue marbles then
yellow = 5b + 7 and
b + 5b + 7 = 37, that is
6b + 7 = 37 ( subtract 7 from both sides )
6b = 30 ( divide both sides by 6 )
b = 5
Thus there are 5 blue and 5(5) + 7 = 25 + 7 = 32 yellow marbles
$0.20 per candy bar
There are 50 candy bars per box. It's costing the school $30/50=$0.60 per candy bar to buy. The school sells each candy bar for $0.80, making a profit of $0.20 per candy bar.
