Central Tendency & DispersionMTP Dec 2023 Series IIQuestion 2928 of 473
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The average age of a group of 10\displaystyle 10 students was 20\displaystyle 20 years. The average age is increased by two years when two new students joined the group. What is the average age of two new students who joined the group ?

Options

A22\displaystyle 22 years
B30\displaystyle 30 years
C44\displaystyle 44 years
D32\displaystyle 32 years
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Correct Answer

✅ Option d — 32\displaystyle 32 years

All Options:

  • A22\displaystyle 22 years
  • B30\displaystyle 30 years
  • C44\displaystyle 44 years
  • D32\displaystyle 32 years

Detailed Solution & Explanation

**Step 1: Total age of original 10 students.** Total10=10×20=200 years\text{Total}_{10} = 10 \times 20 = 200 \text{ years} **Step 2: New total after 2 new students join.** New number of students =10+2=12\displaystyle = 10 + 2 = 12. New average =20+2=22\displaystyle = 20 + 2 = 22 years. New total=12×22=264 years\text{New total} = 12 \times 22 = 264 \text{ years} **Step 3: Sum of ages of 2 new students.** Sum of 2 new=264−200=64 years\text{Sum of 2 new} = 264 - 200 = 64 \text{ years} **Step 4: Average age of 2 new students.** Average=642=32 years\text{Average} = \frac{64}{2} = 32 \text{ years} **Note:** The computed average is **32 years** (Option D), not 44 years (Option C). Hence, **Option D** is the correct answer.

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