Question 1141699
Jose recently took a history test that had certain questions worth three points each.
 He correctly answered the same number of 3-point questions as 5-point questions, and earned a score of 72 points.
 How many 5-point questions did he answer correctly? 
:
let a = no. of 3 pt and no. of 5 pt questions
3a + 5a = 72
8a = 72
a = 72/8
a = 9 ea 5 pt questions  (and 9 ea 3 point questions)
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:
:
Check: 3(9) + 5(9) = 72