Question

A number, half of that number, and one fifth of that number are added. The result is 51. What is the original number?

Answer 1

Let the original number be ‘x’
Then half of that number= 1/2x or simply x/2
Similarly one fifth of that number = x/5
According to the question
x+x/2+x/5=51
Taking LCM
10x/10+2x/10+5x/10=51
Multiplying 10 throughout
10x+2x+5x=510
17x=510
x=510/17
Therefore x=30