Of the three numbers, the first is twice the second and the second is twice the third. The average of the reciprocal of the numbers is $$\frac{7}{72}$$ . The numbers are:
A. 16, 8, 4
B. 20, 10, 5
C. 24, 12, 6
D. 36, 18, 9
Answer: Option C
Solution(By Examveda Team)
Let the number be x.Then, second number = 2x.
First number = 4x.
∴ $$\frac{1}{x}$$ + $$\frac{1}{2x}$$ + $$\frac{1}{4x}$$ = $$\frac{7}{72}$$ × 3
⇒ $$\frac{7}{4x}$$ = $$\frac{7}{24}$$
⇒ 4x = 24
⇒ x = 6
So, the number are 24, 12 and 6
Related Questions on Average
A. 125 km/hr
B. 75 km/hr
C. 135 km/hr
D. 120 km/hr
Join The Discussion