Statistics And Probability Question 388
Question: The average marks obtained by the students in a class are 43. If the average marks obtained by 25 boys are 40 and the average marks obtained by the girl students are 48, then what is the number of girl students in the class?
Options:
A) 15
B) 17
C) 18
D) 20
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Let number of girls student be x Sum of marks $ =25\times 40+x\times 48 $ Total students $ =25+x. $
$ \therefore 43=\frac{25.40+x.48}{x+25} $
$ \Rightarrow 43x+43.25=25.40+x.48 $
$ \Rightarrow 5x=3.25\Rightarrow x=15 $
BETA
