Question

What is the least number that must be subtracted from 30,70,and 190 such that the resultant numbers are in continued proportion ?

Answer 1

Answer:

10

Step-by-step explanation:

Let the least number be x.

Then,

30 - x : 70 - x : : 70 - x : 190 - x

or, 30 - x/70 - x = 70 - x/190 - x

or, (30 - x) × (190 -x) = (70 - x) × (70 - x)

or, 5700 - 190x - 30x + x^2 = 4900 - 70x - 70x + x^2

or, 5700 - 220x +x^2 = 4900 - 140x + x^2

or, 5700 - 4900 + x^2 - x^2 = -140x + 220x

0r, 800 = 80x

or x = 800/80 = 10