Finding the Percentage Increase or Decrease in Given Situations

Q. In measuring the sides of a rectangle, errors of $5\%$ and $3\%$ in excess are made. The error percent in the calculated area is

1. $8.15\%$
2. $8.35\%$
3. $7.15\%$
4. $6.25\%$

Q.

Find the number that when increased by $20\%$ becomes $500$ ?

Q.

Find the number when decreased by $40\%$ become $140$?

Q.

A number is increased by 10% and then reduced by 10%. What is the effective change in the original number?

1. Doesn’t change

2. Decreases by 1%

3. Increases by $1\%$

4. Increases by 10%

Q. Side of square is increased by $10\%$ find the percent increase in its area?

Q.

If the present petrol price is ₹50, then what is the new price when:

i) there is an increase of 20% on the original price?

ii) there is a decrease of 10% on the original price?

1. ₹45, ₹60

2. ₹80, ₹75

3. ₹60, ₹45

4. ₹75, ₹80

Q.

The number obtained after increasing $200$ by $20$% is ____.

1. 240

2. 210

3. 222

4. 220

Q. A number is increased by $10\%$ and then reduced by $10\%$. What is the effective increase or decrease in the original number?

1. Decreases by $1\%$
2. None of these
3. Doesn’t change
4. Increases by $1\%$

Q.

In measuring the length and breadth of a rectangle, errors of $5\%$ and $3\%$ in excess, respectively, are made. The error percent in the calculated area is

1. $7.15\%$

2. $6.25\%$

3. $8.15\%$

4. $8.35\%$