What number must be added to each of the numbers 15, 9 and 5 so that the resulting numbers maybe in a continued proportion?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 3.
Formula used:
If a, b and c are in continued proportion then
a/b = b/c, b2 = ac
Calculations:
Let x be added to the numbers then
⇒ (9 + x)2 = (15 + x)(5 + x)
⇒ x2 + 81 + 18x = 75 + 20x + x2
⇒ 2x = 6
⇒ x = 3