Statistics And Probability Question 553
Question: In a class of 100 students there are 70 boys whose average marks in a subject are 75. If the average marks of the complete class are 72, then what are the average marks of the girls
[AIEEE 2002]
Options:
A) 73
B) 65
C) 68
D) 74
Show Answer
Answer:
Correct Answer: B
Solution:
Let the average marks of the girls students be x, then $ 72=\frac{70\times 75+30\times x}{100} $ (Number of girls =100?70 = 30) i.e., $ \frac{7200-5250}{30}=x $ ; \ x = 65.
BETA
