Question

A number is decreased by 10 and the new number so obtained is increased by 25; the result is 90. Find the number

• A. 65
• B. 90
• C. 75
• D. 100

Answer 1

The correct option is C

75

Let the number be x
The number is decreased by 10 = x-10
New number (x -10) is increased by 25 = (x -10) +25
Forming the equation:
(x -10) +25 =90
[rearranging the terms]
= x -10 +25 = 90
= x +15 = 90
= x = 90- 15 [when +15 is transposed to RHS it becomes -15]
$\Rightarrow$ x = 75