Q. 1: Suppose a shopkeeper has bought 1 kg of apples for 100 rs. And sold it for Rs. 120 per kg. How much is the profit gained by him?

Solution:

Cost Price for apples is 100 rs.

Selling Price for apples is 120 rs.

Then profit gained by shopkeeper is ;

P = SP – CP

P = 120 – 100

P = Rs. 20/-

Q.2: For the above example calculate the percentage of the profit gained by the shopkeeper.

Solution:

We know,

Profit percentage = (Profit /Cost Price) x 100

Therefore,

Profit percentage = (20/100) x 100

Profit Percentage = 20%.

Q.3: A man buys a fan for Rs. 1000 and sells it at a loss of 15%. What is the selling price of the fan?

Solution: 

Cost Price of the fan is Rs.1000

Loss percentage is 15%

As we know,

Loss percentage = (Loss/Cost Price) x 100

15 = (Loss/1000) x 100

Therefore,

Loss = 150 Rs.

As we know,

Loss = Cost Price – Selling Price

So, Selling Price = Cost Price – Loss

= 1000 – 150

Selling Price = R.850/-

Q.4: If a pen cost Rs.50 after 10% discount, then what is the actual price or marked price (MP) of the pen?

Solution:

Since, we know;

MP – D = SP

where MP is marked price, D is discount, SP is selling price.

Percentage discount, D% = D/MP x 100

⇒ D = (D% x MP)/100

Substitute the value of D in the above formula.

MP – (D% x MP)/100 = SP

MP x (100-D%)/100 = SP

Putting the given values in the formula

MP x (100 – 10) /100 = 50

MP x (90/100) = 50

MP = (50 x 100)/90

MP = Rs. 55.55/-