A number is first decreased by 25%. The decreased number is then incre...
Let the number is a
a – (75/100)*a*(120/100) = 40
we will get a = 400
View all questions of this testA number is first decreased by 25%. The decreased number is then incre...
Given:
Original number is decreased by 25% and then increased by 20%. The resulting number is less than the original number by 40.
Let the original number be x
Decreased number:
25% of x = 0.25x
Decreased number = x - 0.25x = 0.75x
Increased number:
20% of decreased number = 0.2 * 0.75x = 0.15x
Increased number = 0.75x + 0.15x = 0.9x
Given condition:
0.9x = x - 40
Solving the equation:
0.9x = x - 40
0.9x - x = -40
-0.1x = -40
x = -40 / -0.1
x = 400
Therefore, the original number is 400. So, option 'D' is correct.