If 36 : 84 :: 42 : X, then the value of X, is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 98
The statement 36 : 84 :: 42 : X says that the two ratios are equal, \(\frac{36}{84}=\frac{42}{X}\). In a proportion, the product of the extremes equals the product of the means, so \(36\times X=84\times42\).
\(\displaystyle X=\frac{84\times42}{36}\)
\(\displaystyle X=\frac{7\times42}{3}=7\times14=98\)