RRB Group-D Model Paper 19 with answers for online practice

A - B = 3, B + C = 78, C + D = 33 and the average age of the family is 34 years
Total age of the family = 4 × 34 = 136 years
A + B + C + D = 136
⇒ A + B = 136 – 33
A + B = 103 years
A – B = 3 years
∴ A = 53 years
B = 103 – 53 = 50 years
Also C + B = 78
⇒ C = 78 – 50 = 28 years
∴ B – C = 50 – 28 = 22 years