A number is first increased by 12% and then increased by 23%. The number, so obtained, is now decreased by 34%. What is the net increase or decrease percent in the original number (nearest to an integer)?

Correct option is B

Given:
A number is increased by 12%, then by 23%, and finally decreased by 34%.
Solution:
Let the original number be 100.

The number is first increased by 12%.

New number after 12% increase = 100 + 12% of 100 = 100 + 12 = 112.

The new number is now increased by 23%.

New number after 23% increase = 112 + 23% of 112 = 112 + 25.76 = 137.76.

Now, the number is decreased by 34%.

New number after 34% decrease = 137.76 - 34% of 137.76 = 137.76 - 46.8544 = 90.9056.

The original number was 100, and the final number is 90.9056.

Net change = 90.9056 - 100 = -9.0944.

Net percentage change = $$\frac{(Net \ change) }{ (Original \ number)}\times 100$$​​

Net percentage change = $$(\frac{-9.0944 }{ 100}) \times 100$$​ = -9.0944%.

The net decrease percentage is approximately -9%.