The ratio between the third proportional of 12 and 30 and mean proportional of 9 and 25 is -
A. 2 : 1
B. 5 : 1
C. 7 : 15
D. 9 : 14
Answer: Option B
Solution(By Examveda Team)
Let the third proportional to 12 and 30 be x.Then,
$$\eqalign{ & = 12:30::30:x \cr & \Rightarrow 12x = 30 \times 30 \cr & \Rightarrow x = \frac{{\left( {30 \times 30} \right)}}{{12}} = 75 \cr} $$
∴ Third proportional to 12 and 30 = 75
Mean proportional between 9 and 25
$$\eqalign{ & = \sqrt {9 \times 25} = 15 \cr & \therefore {\text{Required ratio}} = 75:15 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 5:1 \cr} $$
Related Questions on Ratio
If a : b : c = 3 : 4 : 7, then the ratio (a + b + c) : c is equal to
A. 2 : 1
B. 14 : 3
C. 7 : 2
D. 1 : 2
If $$\frac{2}{3}$$ of A=75% of B = 0.6 of C, then A : B : C is
A. 2 : 3 : 3
B. 3 : 4 : 5
C. 4 : 5 : 6
D. 9 : 8 : 10
Join The Discussion