RRB Group-D Model Paper 18 with answers for online practice

Given:
Ratio of present age of sisters = 5 ∶ 7 ∶ 11
Present age of mother = 45 years
Difference between age of elder sister and mother = 23 years
Concept: Calculate the present age of elder sister, then equate with the rest of the ratios to find the present age of youngest sister.
Calculation:
Let the present ages of the 3 sisters = 5x, 7x, 11x
Present age of elder sister = 45 – 23 = 22 years
∵ The present age of elder sister = 11x = 22 years
∴ 11x = 22
⇒ x = 22/11
⇒ x = 2
∴ Present age of youngest sister = 5 × 2 = 10 years
⇒ Her age after 10 years from now = 10 + 10 = 20 years