Numerical: average MCQ — 5 Practice Questions with Answers

Explanation

The four-subject total exceeds the Maths plus Science total by exactly the combined marks of Social Science and English. That combined score is therefore 140. The question asks for the average of these two subjects, so divide 140 by 2 to get 70. A score of 50, 75, or 60 would imply combined marks of 100, 150, or 120 respectively, none of which matches the given difference of 140.

Explanation

Let the batsman’s average after 16 innings be x runs. His total then was 16x. After scoring 90 in the 17th inning, the new average becomes x + 3, so (16x + 90) / 17 = x + 3. This gives 16x + 90 = 17x + 51, hence x = 39 and the new average is 42 runs. An average of 44, 38 or 40 does not satisfy the given increase of exactly 3 after adding the score of 90.

Explanation

The even numbers between 320 and 350 are 322, 324, 326, ..., 348. They form an arithmetic progression, so the average equals the mean of the first and last terms: (322 + 348)/2 = 335. Even if the endpoints 320 and 350 are included, the average remains (320 + 350)/2 = 335. Therefore 332 is not the centre of the sequence, 330 is too low for this range, and 325 is farther below the required average.

Explanation

Let the four numbers be a, b, c, and d. The first three have average 15, so a + b + c = 45. The last three have average 16, so b + c + d = 48. The last number is 19, which gives b + c = 29. Therefore a = 45 - 29 = 16. The values 14, 15, and 17 do not satisfy both average conditions when the last number remains 19.

Explanation

The sum of all 7 numbers is 7 × 39 = 273. The sum of the 3 selected numbers is 3 × 27 = 81. So the sum of the remaining 4 numbers is 273 - 81 = 192. Their average is 192 ÷ 4 = 48. The values 44, 40, and 52 do not match this remaining total; they would imply sums of 176, 160, and 208 respectively, not 192.