The average age of A, B and C is 30 years. If the difference between B's age and A's age is same as the difference between C's age and B's age. If D is 40 years older than B then what is the sum of the age of B and D?

• ক 70 years
• খ 30 years
• গ 80 years
• ঘ 100 years ✅ সঠিক উত্তর