The average marks of three students A, B and C is 48. When another student D…
2026
The average marks of three students A, B and C is 48. When another student D joins the group, the new average becomes 47 marks. If another student E, who has 3 marks more than D, joins the group, the average of the 4 students B,C, D and E becomes 48 marks. How many marks did A get in the exam?
- A.
43
- B.
48
- C.
41
- D.
46
Attempted by 670 students.
Show answer & explanation
Correct answer: A
Solution:
Compute the total for A, B and C from their average: 3 × 48 = 144.
When D joins the group, the average of four students is 47, so the total becomes 4 × 47 = 188. Therefore D = 188 − 144 = 44.
E has 3 marks more than D, so E = 44 + 3 = 47.
The average of B, C, D and E is 48, so their total is 4 × 48 = 192. Thus B + C = 192 − (D + E) = 192 − (44 + 47) = 192 − 91 = 101.
Finally, A = (A + B + C) − (B + C) = 144 − 101 = 43.
Answer: 43 marks.