If the third proportional of 3x2 and 4xy is 48, then find the positive value of y.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 3.
The third proportion of two numbers a and b is c, such that:
⇒ a/b = b/c
Here, a = 3x2, b = 4xy, and c = 48
⇒ 3x2/4xy = 4xy/48
⇒ 3x/4y = xy/12
⇒ 3x × 12 = 4y × xy
⇒ 36x = 4xy2
⇒ y2 = 36x/4x
⇒ y = = 3