Multiple choice

The average score of a class of boys and girls in an examination is N. The ratio of boys and girls in the class is 4:1 .If the average score of the boys is (N+1),then the average score of the girls is-

  1. $\(N-1\)$
  2. $\(N-2\)$
  3. $\(N-4\)$
  4. $\(2N+1\)$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

With boys:girls = 4:1, let 4x boys and x girls total. Class average N gives total score 5xN. Boys contribute 4x(N+1). Girls contribute 5xN - 4xN - 4x = xN - 4x, so girls' average = (xN - 4x)/x = N - 4.

Keep practicing — related questions