The task is to generate the correct answer for a given math problem.

Q: Problem: if a = 105 and a ^ 3 = 21 × 25 × 45 × z , what is the value of z ?

A: 49
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Q: Problem: two cubes have their volumes are in the ratio 1 : 27 . find the ratio of their surface area ?

A: 1 : 9', 'd ) 2 : 7', 'e ) 3 : 11'
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Q: Problem: the average of marks obtained by 120 boys was 38 . if the average of marks of passed boys was 39 and that of failed boys was 15 , the number of boys who passed the examination is ?

A:
115
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