Question 67
The average age of all the students of a class is 18 years, The average age of boys of the class is 20 years and that of the girls is 15 years. If the number of girls in the class is 20, then what is the number of boys in the class?
Solution
Let total number of boys in the class = B
Now,
Average age of the class = $$18 = \frac{20 * B + 15 * 20}{B + 20}$$
18(B + 20) = 20B + 300
18B + 360 = 20B + 300
2B = 60
B = 30
Get AI Help
Video Solution
Click on the Email ☝️ to Watch the Video Solution
SRCC Quant Questions | SRCC Quantitative Ability
SRCC DILR Questions | LRDI Questions For SRCC
SRCC Verbal Ability Questions | VARC Questions For SRCC
Free SRCC Quant Questions
Book Free CAT Mentorship
Get personalized CAT strategy from a 99%iler
500+ students mentored
OTP Verification
Enter the 6-digit code sent to your phone
Booking Summary
Session:Free CAT Mentorship
Phone:
Date:
Time:
Enter OTP
Didn't receive the OTP?
