Find the product xy if, x, 3/2, 6/7, y are in G.P
-
A.
24/49 -
B.
4/7 -
C.
9/7 -
D.
7/4 -
E.
21/8
Correct Answer: Option C
Explanation
In GP, when you are given three consecutive terms, say f, g, h, then
(f times h = g^2)
Given: (x, frac{3}{2}, frac{6}{7}, y), then
(frac{6x}{7} = (frac{3}{2})^2 implies frac{6x}{7} = frac{9}{4} … (i))
Also, (frac{3y}{2} = (frac{6}{7})^2 implies frac{3y}{2} = frac{36}{49} … (ii))
From (frac{6x}{7} = frac{9}{4} implies x = frac{9 times 7}{6 times 4})
(x = frac{21}{8})
Also, (frac{3y}{2} = frac{36}{49} implies y = frac{2 times 36}{3 times 49})
= (frac{24}{49})
(xy = frac{21}{8} times frac{24}{49} = frac{9}{7})