**1. A student finds the average of 10 two digit numbers. If the digits of a number are interchanged, the average increases by 3.6. The difference between the digits of that two digit number is:-**

4

3

2

Solution:

Average increases by 3.6

So total increases = 3.6*10

= 36 (this is the difference between the original and interchanged number)

If the original number is 48 then its reverse is 84 which is 36 greater then the original number

So the difference between the digits = 8-4 = 4

So total increases = 3.6*10

= 36 (this is the difference between the original and interchanged number)

If the original number is 48 then its reverse is 84 which is 36 greater then the original number

So the difference between the digits = 8-4 = 4

**2. A shopkeeper allows a discount of 10% on the marked price of an item. But charges a sales tax of 8% on the discounted price. If the customer pays 3402₹ as the price including the sales tax, then the marked price is :-**

3400

3500

2600

3800

Solution:

let the marked price of item is M.

M×.9×1.08=3402

M=3402÷ (.9×1.08)

M =3500

M×.9×1.08=3402

M=3402÷ (.9×1.08)

M =3500

**3. A car travels from city P to city Q at a constant speed. If its speed increased by 10km/h, it would have been taken one hour lesser to cover the same distance. It would have taken further 45 minutes lesser , if the speed was further increased by 10km/h. The distance between the two cities is :-**

340

420

600

500

**4. First and second numbers are less than a third number by 30% and 37%, respectively. The second number is less than the first by:**

7%

4%

3%

10%

Solution:

Let the third number be 100

Then, first number = 70

Therefore, second number = 63

Hence, required % =(70-63)/70×100

=7/70×100=10%

Then, first number = 70

Therefore, second number = 63

Hence, required % =(70-63)/70×100

=7/70×100=10%

**5. If the height of a triangle is decreased by 40% and its base is increased by 40%, what will be the effect on its area?
**

No change

16% increase

8% increase

16% decrease

Solution:

Required effect =(+40-40-(40 × 40)/100)%

i.e. the area will decrease by 16%.

i.e. the area will decrease by 16%.

**6. In 1 kg mixture of sand and iron, 20% is iron. How much sand should be added so that the proportion of iron becomes 10%?**

1 kg

200 gm

800 mgs

1.8 kg

Solution:

In 1 kg mixture quantity of iron = 200 gm

Let x gm sand should be added, then 10% of (1000 + x) = 200

∴ x = 1000 gm = 1 kg.

Let x gm sand should be added, then 10% of (1000 + x) = 200

∴ x = 1000 gm = 1 kg.

**7. A tradesman gives 4% discount on the marked price and gives 1 article free for buying every 15 articles and thus gains 35%. The marked price is increased above the cost price by:**

40%

39%

50%

20%

**8. The strength of a school increases and decreases in every alternate year by 10%. It started with increase in 2000. Then the strength of the school in 2003 as compares to that in 2000 was:**

Increased by 8.9%

Decreased by 8.9%

Increase by 9.8%

Decreased by 9.8%

**9. The price of cooking oil has increased by 25%. The percentage of reduction that a family should effect in the use of cooking oil, so as not to increase the expenditure on this account, is:**

15%

20%

25%

30%

Solution:

Percentage decrease =r/(100 + r)×100%

=(25/125)×100=20%

=(25/125)×100=20%

**10. Krishnamurthy earns Rs. 15000 per month and spends 80% of it. Due to pay revision, his monthly income has increased by 20% but due to price rise, he has to spend 20% more. His new savings are:**

Rs. 3,400

Rs. 3,000

Rs. 3,600

Rs. 4,000

**11. Population of a town increases 2.5% annually but it is decreased by 0.5% every year due to migration. What will be the approximate percentage increase in 2 years?**

5

4.4

4

3.7

**12. A reduction of 10% in the price of tea enables a dealer to purchase 25 kg more tea for Rs. 22500. What is the reduced price per Kg of tea?**

Rs. 70

Rs. 80

Rs. 90

Rs. 100

Solution:

Required reduced price =(10/100)×(22500/25)= Rs. 90

**13. A work could be completed in 100 days by some workers. However, due to the absence of 10 workers, it was completed in 110 days. The original number of workers was:**

100

110

55

50

Solution:

Let the original number of workers be x.

∴ x workers can do the work in 100 days

(x – 10) workers can do the work in 110 days

⇒ 100x = 110(x – 10)

⇒ 10x = 1100 ⇒ x = 110

∴ x workers can do the work in 100 days

(x – 10) workers can do the work in 110 days

⇒ 100x = 110(x – 10)

⇒ 10x = 1100 ⇒ x = 110

14. A is thrice as good a workman as B, therefore, A is able to finish a piece of work in 60 days less than B. The time (in days) in which they can do it working together is:

14. A is thrice as good a workman as B, therefore, A is able to finish a piece of work in 60 days less than B. The time (in days) in which they can do it working together is:

22

22 (1/2)

23

23 (1/4)

**15. If A works alone, he would take 4 days more to complete the job than if both A and B worked together. If B worked alone, he would take 16 days more to complete the job than if A and B work together. How many days would they take to complete the work if both of them worked together?**

10 days

12 days

6 days

8 days