Let the single digit number be x.vinay1983 wrote:12 is added to a single digit number. The resulting number is increased by the same percent as was done initially to the single digit number to obtain a result of 75. What was the single digit number?
OA: 3
x is increased by 12:
Percentage increase = ((12+x)-x)/x * 100% = (1200/x)%
The resultant number is increased by the same percentage to get 75:
(12+x)(100 + 1200/x)/100 = 75
(12+x)(1+12/x) = 75
(12+x)(x+12)/x = 75
(12+x)^2 = 75x
144 + 24x + x^2 = 75x
x^2 - 51x + 144 = 0
(x-48)(x-3)=0
So x = 48 or x = 3
Since x is a single digit number,
[spoiler]x = 3[/spoiler]
Cheers[/i]
