Multiple choice

The average of the test scores of a class of ‘m’ students is 70 and that of ‘n’ students is 91. When the scores of both the classes are combined, the average is 80. What is n/m? 'm' छात्रों के एक कक्षा के परीक्षा के स्कोर का औसत 70 है और ‘n’ छात्रों के कक्षा का औसत 91 है । जब दोनों वर्गों के स्कोर संयुक्त किये जाते हैं तो औसत 80 है । n/m क्या है?

  1. 10/13

  2. 10/11

  3. 11/10

  4. 13/10

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total marks = 70m + 91n. Combined average: (70m + 91n)/(m+n) = 80. Solving: 70m + 91n = 80m + 80n. This gives 11n = 10m, so n/m = 10/11. This uses the weighted average formula where overall average lies between individual averages.