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Practice Time 7A

1. If 7% of a number is 42, then find the number.
2. From a drum containing 225 L of petrol, 4.5 L of petrol was wasted due to a leakage. Find the leakage
percentage of petrol.
3. A taxi is filled with 15 kg of CNG before starting a journey. After reaching the destination, 2.25 kg
of CNG is left. What per cent of CNG was consumed during the journey?
4. Nagma and Shipra work in the same company but they have different designations. Nagma’s salary
is `45,000 and she gets an increment of 12%. Find her new salary. While Shipra’s new salary after
an increase of 8% becomes `81,000. What was her previous salary?
5. A car running at the speed of 45 km/h increases its speed to 60 km/h in the next few seconds. Find
the percentage increase in speed.
6. A fruit seller had some oranges. He sells 40% of the oranges and still has 180 oranges. Find the
number of oranges he originally had.
7. If 80% of the subject experts are female and the number of male subject experts is 25, what is the
number of female subject experts?
8. A number was increased by 20% and then decreased by 20%. Find the net increase or decrease per
cent.

9. The cost of a theatre ticket is increased by 40% for a special movie. What is the new price if the
normal price is `320?

10. The original cost of a motorcycle was `80,000. In two years, its cost has decreased by 22%. What is
its cost now?

11. A man gives 40% of his money to his children and 20% of the remaining amount to a trust. If he is
still left with `96000, what did he originally have?

12. The human body is made up mostly of water. In fact, about 67% of a person’s total body weight is
water. If Nanda weighs 60 kg, how much of her weight is water?

Profit and Loss

Cost Price/Selling Price

• The amount paid to purchase an article is called its cost price (CP).
• The amount at which an article is sold is called its selling price (SP).

• Extra expenses like cartage, labour charges, cost of repairing, etc. are called overhead expenses,
which are to be included in the cost price.
Profit/Loss

• When the selling price (SP) of an article is greater than the cost price (CP), then there is a profit
or gain. That is, if SP > CP, then

Profit = SP – CP ⇒ SP = CP + Profit ⇒ CP = SP – Profit
• When the cost price of an article is greater than the selling price, then there is a loss. That is,
if CP > SP, then

Loss = CP – SP ⇒ CP = SP + Loss ⇒ SP = CP – Loss

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