question of percentage:-

A number is increased by 15% and then decreased by 10%. find the net increase or decrease per cent.

3.5

To find the net increase or decrease percentage, we can follow these steps:

Step 1: Let's assume the original number to be "x".
Step 2: Calculate the increase by multiplying the original number (x) by 15% (or 0.15). This gives us an increase of 0.15x.
Step 3: Add the increase to the original number: x + 0.15x = 1.15x.
Step 4: Calculate the decrease by multiplying the increased number (1.15x) by 10% (or 0.10). This gives us a decrease of 0.10 * 1.15x = 0.115x.
Step 5: Subtract the decrease from the increased number: 1.15x - 0.115x = 1.035x.

Now, to calculate the net increase or decrease percentage, we need to compare the difference (1.035x - x) to the original number (x).

Net increase or decrease percentage = (Difference / Original number) * 100.

Let's plug in the values:

Difference = 1.035x - x = 0.035x
Original number = x

Net increase or decrease percentage = (0.035x / x) * 100
= 3.5%

Therefore, the net increase or decrease percentage is 3.5%.

1.15*0.90 = 1.035

so, a net 3.5% increase