Average Ques 8
Question-
The average age of some males and 15 females is 18 years. The sum of the ages of 15 females is 240 years and average age of males is 20 years. Find the number of males.
(1) 8
(2) 7
(3) 10
(4) 15
(5) None of these
Show Answer
Correct Answer: (4)
Solution: (4)
Let the number of males be $x$.
$\therefore 18=\frac{x \times 20+240}{x+15}$
$\Rightarrow 18 x+270=20 x+240$
$\Rightarrow 20 x-18 x=270-240$
$\Rightarrow 2 x=30$
$\Rightarrow x=\frac{30}{2}=15$
BETA
