Q8 of 59 Page 61

The ratio of present ages of Rehana and her mother is 2 : 7. After 2 years, the ratio of their ages will be 1 : 3. What is Rehana's present age?

Given: Ratio of present age of Rehana and her mother = 2:7


So, let present age of Rehana = 2x


∴ Present age of her mother = 7x


After 2 years, age of Rehana = (2x + 2) years


After 2 years, age of her mother = (7x + 2) years


Now, given that after two years ratio of their ages will be 1:3.



On cross multiplying, we get:


6x + 6 = 7x + 2


⇒ 7x – 6x = 6 – 2


⇒ x = 4


∴ Present age of Rehana = 2x = (2 × 4) years = 8 years


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