exam Maths Puzzle Numerical Ability

The average age of three boys is 25 years and their ages are in the proportion 3:5:7.The age of the youngest boy is
a)21 b)18 c)15 d)9

Read Solution (Total 0)

exam Other Question

The problem is:

5 + ln x^2 = 4

I have absolutely no idea how to solve this problem.

Please and thank you in advance ! how many gallons of a 5% acid solution should be mixed with 30 gallons of a 10% acid solution to obtain a mixture that is 8% acid?