A number is first decreased by 15% and then increased by 20%. The number so
obtained is 78 more than the original number. The original number is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 3900.
Let the original number be x
x−15% of x = 0.85x
0.85x + 20% of 0.85x = 1.02x
1.02x − x = 78
0.02x = 78
x = 78/0.02 = 3900