Find the third proportional to 25 and 30. · ABC26GN3191

Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: Indian Railway Gr. ‘D’ Exam 2014

Find the third proportional to 25 and 30.

(a)36

(b)32

(c)34

(d)38

Answer

Answer (as printed): A

Explanation

Let the third proportional be $x$. $25 : 30 :: 30 : x \Rightarrow 25 \times x = 30 \times 30$ $$\Rightarrow x = \frac{30 \times 30}{25} = 36$$

Explanation as extracted from the printed page; notation may be imperfect.

Study loop for Ratio and Proportion