The fourth proportion to 12,24 and 27 is the same as the third proportion to A and 36 . What is the value of A?
Answer & explanation
Correct answer: option 2
Using direct formula for the fourth proportional,
d = \(\frac{b\; \times\; c}{a}\)
= \(\frac{24\; \times\; 27}{12}\) = 54
The third proportional of A and 36 is 54
Third proportional is = c = \(\frac{b^2}{a}\)
⇒ 54 = \(\frac{36^2}{A}\)
⇒ A = \(\frac{36 × 36}{54}\)
⇒ A = 24