Question

Q. In an exam, the average marks scored by 25 students is 18. The average marks scored by the first 12 students is 14 and by last 12 students is 17. How many marks did the 13th student score?

• A. 88
• B. 78
• C. 68
• D. 58

Answer 1

The correct option is B 78

$18\times 25=12\times 14+12\times 17+X$

$18\times 25=12\times (14+17)+X=12\times 31$

$X=450-372=78Marks$