Solve these sample questions on percentage

This article is in continuation to the last article focusing on the percentage topic. Here are some practice questions along with solutions that will help you in your preparation for the State government recruitment jobs. 1. An alloy contains the copper and aluminum in the ratio of 3:5. While making the weapons from this alloy, […]

This article is in continuation to the last article focusing on the percentage topic. Here are some practice questions along with solutions that will help you in your preparation for the State government recruitment jobs.

1. An alloy contains the copper and aluminum in the ratio of 3:5. While making the weapons from this alloy, 20% of the alloy got destroyed. If there is 25 kg of aluminum in the weapon, then the weight of the alloy required is?

---

a) 40kg b) 45kg c) 50kg d) 55kg

Ans: c

Solution: Copper : Aluminum

3 : 5
×5 : × 5
Weapon –>; 15 25 = 40kg
Let total alloy = x kg

80% of x = 40

x = 40 × 100/80 = 50kg

2. 20% of the toys produced in a factory were defective and 25% of the remaining was damaged. If 4,800 toys were in good condition, then what was the original number of toys produced?

a) 8000 b) 7500 c) 9000 d) 7000

Ans: a

Solution: 20% = 20/100 = 1/5, 25% = 25/100 = 1/4

5 : 4
4 : 3
20 : 12
12 –>; 4800
1 –>; 400
20 × 400 = 8000

3. What is the percentage change in the result when we add 75 to a certain number x, instead of subtracting 75 from the same number x?

a) 25% b) 50% c) 75% d) Can’t be determined

Ans: d

Solution: Use some different values of x, then verify

Let x = 100

The percentage error = (175-25) / 25 × 100%

= 600%
Let x = 150

The percentage error = (225-75) / 75 × 100%

= 200%
Hence, we can’t determine.

4. In a garden 60% of the trees are coconut trees, 25% of the number of coconut trees are mango trees and 20% of the number of mango trees are apple trees. If the number of apple trees in the garden is 2,880, then find the total number of trees in the garden.

a) 94,000 b) 96,000 c) 98,000 d) 1,00,000

Ans: b

Solution: 60% = 60/100 = 3/5, 25% = 25/100 = 1/4, 20% = 20/100 = 1/5

Let the total number of trees in the garden = 100

100 –>; 3/5 60 –>; 1/4 15 –>;1/5 3

total trees coconut trees mango trees apple trees

3 –>; 2880

1 –>; 960

100 –>;100 × 960

= 96,000

5. A grocery store purchases 600 bottles of juice packed by two different sellers. 20% goods are taken by first seller and 80% by the second. The cost price of one bottle is Rs 25. After observing the second seller’s goods, the shopkeeper finds that 25% goods can be used for a period of one day. He decides to return the goods. How much money will he get back from second seller?

a) Rs 3,000 b) Rs 3,250 c) Rs 3,500 d) Rs 3,750

Ans: a

Solution: 600

First seller Second seller

(20%) (80%)

120 480
25% 75%
120 360

Therefore, the money received for spoiled bottles by second seller = 120 × 25 = Rs 3,000.

6. A drug supervisor rejects 0.05% of medicine as defective medicines. How many medicines will be tested to reject 4 medicines?
a) 5000 b) 6000 c) 7000 d) 8000

Ans: d

Solution: 100 –>; 0.05

? –>; 4
? = (100 × 4) / 0.05
= 8000

7. The amount of glucose required to prepare 250 gms of solution in which the glucose content is 5% will be

a) 12.5g b) 125gm c) 25gm d) 50 gm

Ans: a

Solution: 100 –>; 5%

250 –>; ?

? = (5 × 250) / 100 = 12.5gm

To be continued…

M.Venkat

Director
MVK Publications
Dilsukhnagar
7671002120