Mathematics: Questions related to profit and loss | Brain booster series

Ques: 1. The rate of ghee decreased by 20%. If earlier Ghee was Rs.25 per kg, then what will be the cost of Ghee per kg now?

Solution: Given,

Earlier price of ghee = 25

Price decreased = 20%

Now, price after decreasing 20% = 

First of all 20% of 25 is = 25*20/100 = 5

New price will be = Previous price- decreased price 

i.e., 25-5 = 20

Therefore, new price of ghee is Rs. 20.

Ques: 2. If the selling price of 3 articles is equal to the cost price of 4 articles, then what will be profit percentage ?

Solution: 

Concept, If selling price of x commodity is equals to cost price of y commodity in that condition there will be always profit, 

Formula used- (y-x)/x * 100

Therefore, 4-3/3 * 100 = 33⅓% 

Profit percentage is 33⅓%.

Ques: 3. A shopkeeper sells his goods at cost price, but uses 900 grams of watts instead of 1 kg, then what is his profit percentage

Solution: When a seller sells an article at cost price but instead of x gram watt he uses y gram watt, then the seller's percentage profit or loss =(x-y)/y * 100

Therefore, 1000-900/900 * 100

100/9 = 11⅑ Ans.

Profit percentage is 11⅑%.

Ques: 4. A cow was bought for Rs 320. For how much should it be sold now so that there is a profit of 12½%?

Solution: Given,

Cost price of cow= 320

To find = selling price (sp)

We know that, 

Selling price = Cost price (1+r%)

Here Cp= 320, r% = 12.5%, Sp=?

Keeping value, 

Sp= 320* (1+12.5%)

Sp= 320× (1+125/1000)

Sp= 320× 9/8

Sp= 360

Therefore, selling price must be Rs. 360 to get a profit of 12.5%.

Ques: 5. What will be the selling price of an article worth Rs 300 on which 20 percent profit is made even after spending Rs 150 on repairs?

Solution: Given, 

Cp = 300

Repairs= 150

Total price after repairing = 450

Selling price= Cp(1+r%)

Sp= 450×(1+20%)

Sp= 450×6/5

Sp= 540

Therefore, selling price must be Rs. 540 to get a profit of 20% after Rs. 150  of repairs.