Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: · Marks: · Difficulty:
The third proportional to 38 and 15 is
(a)$\frac{15 \times 15}{38}$
(b)$\frac{38 \times 15}{2}$
(c)$\frac{38 \times 38}{15}$
(d)$\frac{15}{38 \times 38}$
Answer
Answer (as printed): A
Explanation
Let the third proportional to 38 and 15 be $x$. $$\text { Then, } 38: 15:: 15: x \Leftrightarrow 38 x=15 \times 15 \Leftrightarrow x=\frac{15 \times 15}{38} \text {. }$$
Explanation as extracted from the printed page; notation may be imperfect.