# 4 years ago the average age of A, B, and C was 34 years and the present average age of A and B is 28 years. After 2 years, the average age of C and D

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4 years ago the average age of A, B, and C was 34 years and the present average age of A and B is 28 years. After 2 years, the average age of C and D would be 65 years. Find the present age of D.
1. 56 years
2. 62 years
3. 60 years
4. 68 years
5. 55 years

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Correct Answer - Option 4 : 68 years

Given:

Average age of A, B, and C, 4 years ago = 34 years

Present average age of A and B = 28 years

Average age of C and D after 2 years = 65 years

Formula used:

Average = Sum of units/Number of units

Calculation:

Sum of age of A, B, and C, 4 years ago = 34 × 3 = 102 years

Present sum of their ages = 102 + (3 × 4) years

⇒ 102 + 12 years

⇒ 114 years

Now, Sum of age of A and B = 28 × 2 years

⇒ 56 years

Age of C = (114 – 56) years

⇒ 58 years

Age of C after 2 years = 60 years

Sum of age of C and D after 2 years = (65 × 2) years

⇒ 130 years

Age of D after 2 years = (130 – 60) years

⇒ 70 years

Present age of D = (70 – 2) years

⇒ 68 years

∴ The average age of D is 68 years