Average & Problems on Ages Quiz | Quantitative Aptitude MCQ Practice for IBPS AFO 2026

1

Average of four numbers is 64. If 3 is added to the first number, multiplied to the second, subtracted from the third and divided to the last one, then all the values are the same. Find the difference between the 2nd highest and the smallest number?

Solution & Explanation Let the four numbers be a, b, c, and d. Their sum is 4 * 64 = 256. If a+3 = 3b = c-3 = d/3 = k, then a=k-3, b=k/3, c=k+3, d=3k. Substituting these into the sum equation: (k-3) + (k/3) + (k+3) + (3k) = 256. This simplifies to 5k + k/3 = 256, or 16k/3 = 256, so k=48. The numbers are a=45, b=16, c=51, d=144. The smallest number is 16 and the second highest number is 51. The difference is 51 - 16 = 35.

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2

The average of a collection of 20 measurements was calculated to be 56 cm. But later, it was found that a mistake had occurred in one of the measurements which was recorded as 64 cm, but should have been 61 cm. The correct average must be?

Solution & Explanation The initial sum of 20 measurements was 56 * 20 = 1120 cm. To correct the sum, subtract the incorrectly recorded value (64 cm) and add the correct value (61 cm): 1120 - 64 + 61 = 1117 cm. The number of measurements remains 20. The correct average is 1117 / 20 = 55.85 cm.

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3

Four years hence sum of A and B will be 16 more than present sum of B and C. Four years ago sum of A and C was 32. Find present age of C.

Solution & Explanation (A+4+B+4) = (B+C)+16 => A-C=8. (A-4)+(C-4)=32 => A+C=40. Solving A-C=8 and A+C=40 gives C=16.

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4

Ratio of ages of Ram and Rahim 10 yrs ago was 1:3. Ratio five years hence will be 2:3. Find present ratio.

Solution & Explanation (x+15)/(3x+15)=2/3 => 3x+45=6x+30 => 3x=15 => x=5. Present ages: 15, 25. Ratio = 15:25 = 3:5.

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5

Average marks of class XI are X. When average of 15 students reduced by 6, class average reduces by 1.875. Class XII has 16 more students and total marks 5120. Find average marks of class XII.

Solution & Explanation 1.875N = 15×6 => N=48. XII students = 48+16=64. Avg = 5120/64 = 80.

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Average & Problems on Ages Quiz for IBPS AFO 2026

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