Formula: Profit or Gain = S.P. – C.P.
Formula: Loss = Cost price (C.P.) – Selling Price (S.P.)
Below is the list of some basic formulas used in solving questions on profit and loss:
The above two formulas can be stated as,
If an article is sold at a gain of 10%, then SP = 110% of CP.
If an article is sold at a loss of 10%, then SP = 90% of CP.
Question 1: An article is purchased for Rs. 450 and sold for Rs. 500. Find the gain percent.
Gain = SP – CP = 500 – 450 = 50.
Gain% = (50/450)*100 = 100/9 %
Question 2: A man sold a fan for Rs. 465. Find the cost price if he incurred a loss of 7%.
CP = [100 / (100 – Loss %)] * SP
Therefore, the cost price of the fan = (100/93)*465 = Rs. 500
Question 3: In a transaction, the profit percentage is 80% of the cost. If the cost further increases by 20% but the selling price remains the same, how much is the decrease in profit percentage?
Let us assume CP = Rs. 100.
Then Profit = Rs. 80 and selling price = Rs. 180.
The cost increases by 20% → New CP = Rs. 120, SP = Rs. 180.
Profit % = 60/120 * 100 = 50%.
Therefore, Profit decreases by 30%.
Question 4: A man bought some toys at the rate of 10 for Rs. 40 and sold them at 8 for Rs. 35. Find his gain or loss percent.
Cost price of 10 toys = Rs. 40 → CP of 1 toy = Rs. 4.
Selling price of 8 toys = Rs. 35 → SP of 1 toy = Rs. 35/8
Therefore, Gain = 35/8 – 4 = 3/8.
Gain percent = (3/8)/4 * 100 = 9.375%
Question 5: The cost price of 10 pens is the same as the selling price of n pens. If there is a loss of 40%, approximately what is the value of n?
Let the price of each pen be Re. 1.
Then the cost price of n pens is Rs. n and
the selling price of n pens is Rs. 10.
Loss = n-10.
Loss of 40% → (loss/CP)*100 = 40
Therefore, [(n-10)/n]*100 = 40 → n = 17 (approx)
Question 6: A dishonest merchant sells his grocery using weights 15% less than the true weights and makes a profit of 20%. Find his total gain percentage.
Let us consider 1 kg of grocery bag. Its actual weight is 85% of 1000 gm = 850 gm.
Let the cost price of each gram be Re. 1. Then the CP of each bag = Rs. 850.
SP of 1 kg of bag = 120% of the true CP
Therefore, SP = 120/100 * 1000 = Rs. 1200
Gain = 1200 – 850 = 350
Hence Gain % = 350/850 * 100 = 41.17%
Question 7: A man bought two bicycles for Rs. 2500 each. If he sells one at a profit of 5%, then how much should he sell the other so that he makes a profit of 20% on the whole?
Before we start, it’s important to note here that it is not 15% to be added to 5% to make it a total of 20%.
Let the other profit percent be x.
Then, our equation looks like this.
105/100 * 2500 + [(100+x)/100] * 2500 = 120/100 * 5000 → x= 35.
Hence, if he makes a profit of 35% on the second, it comes to a total of 20% profit on the whole.
Question 8: A shopkeeper allows a discount of 10% on the marked price and still gains 17% on the whole. Find at what percent above the cost price did he mark his goods.
Let the cost price be 100. Then SP = 117.
Let the marked price be x.
So, 90% of x = 117 → x = 130.
Therefore, he marked his goods 30% above the cost price.
Question 9: A shopkeeper offers a discount of 20% on the selling price. On a special sale day, he offers an extra 25% off coupon after the first discount. If the article was sold for Rs. 3600, find
Let the marked price of the article be x.
First a 20% discount was offered, on which another 25% discount was offered.
So, 75% of 80% of x = 3600
75/100 * 80/100 * x = 3600 → x = 6000.
So the article was marked at Rs. 6000.
Cost price of the article = [100/(100+80)]*3600 = Rs. 2000.
It is important to note here that this DOES NOT equal to a 45% discount on the whole. When different discounts are applied successively, they CANNOT be added.
If the loss incurred in a transaction is 3/5th of the selling price, find the loss percent.
Let the selling price be x. loss is 3x/5.
Cost price = Selling price + loss = x + 3x/5 = 8x/5
Loss% = (3x/5) / (8x/5) * 100 = 37.5%
After applying successive discounts of 10% and 5% on an article, it was sold at Rs. 513. Find the marked price of the article.
A. Rs. 590
B. Rs. 600
C. Rs. 603.5
90/100 * 95/100 * x = 513 → x = 600
A sells a set of books to B for Rs. 300 at a profit of 25%. B sells it to C at a loss of 10%.
i) What was the original price paid by A?
ii) What was the price paid by C to B?
A. 240, 260
B. 250, 270
C. 250, 260
D. 240, 270
i. Price paid by A (cost price paid by A) = [100/(100+25)]*300 = Rs. 240.
ii. Price paid by C (Selling price by B to C) = [(100-10)/100]*300 = Rs. 270.