SOLUTION: Josh got a score of 67 on his first math test and a score of 78 on his second math test. Each of these tests is worth 25% of his final grade. His third math test is worth 50%

Algebra ->  Average -> SOLUTION: Josh got a score of 67 on his first math test and a score of 78 on his second math test. Each of these tests is worth 25% of his final grade. His third math test is worth 50%       Log On


   



Question 35281: Josh got a score of 67 on his first math test and a score of 78 on his
second math test. Each of these tests is worth 25% of his final grade. His
third math
test is worth 50% of his final grade. What score must Josh get on his third
math test in order to have a final grade of 85?

Answer by narayaba(40) About Me  (Show Source):
You can put this solution on YOUR website!
Let the score required by josh in the third math test to have a final grade of 85 be denoted x
the first two math test account for 25% for his final grade and the third maath test is worth 50% for final grade
25% is 25/100 = 1/4 and 50% is 50/100 = 1/2
67*(1/4) + 78*(1/4) + x*(1/2) = 85
mutliplying by 4 both sides of equation
67*1 + 78*1 +2*x = 85*4
145 + 2*x = 340
2*x = 195
x = 97.5
Josh has to score 97.5 in his third math test inorder to get 85 in his final grade