Question

Which of the following is incorrect-
(A) If quantites a, b, c, d are in
proportion, then a x d = b *c
(B) If quantites a, b, c, d are in
proportion, then ac = bd
(C) Inverse proportion of a : b is b:a.
(D) If quantites a, b, c are in G.P., then
b² = ac​

Answer 1

Answer:

b is the incorrect answer