Delhi Police Constable Exam Model Paper 3

Tips & Tricks
Given:Sum of ages of Mallika and Uttam is 40 years
Five years ago, the ratio of their ages = 7: 8
Calculation:
Let the ages of Mallika and Uttam 5 years ago be 7x and 8x
Present age ratio = (7x + 5): (8x + 5)
According to the question,
Sum of ages of Mallika and Uttam is 40 years
⇒ $7\mathit{x}+5+8\mathit{x}+5=40$
⇒ $15\mathit{x}=30\mathit{o}\mathit{r}\mathit{x}=2$ years
⇒ Age of Mallika 5 years ago = $7\mathit{x}=14$
∴ Present age of Mallika = 14 + 5 = 19 years.
Short Trick:
Given that 5 years ago, Age of Mallika was 7x
∴ The present age of Mallika will be that option from which if we subtract 5, it will be multiple of 7 i.e. (19 - 5) = 14 which is multiple of 7.
Hence, 19 years is the correct answer.