**1.The ratio of number of boys to that of girls in a group becomes 2 : 1 when 15 girls leave. But, afterwards, when 45 boys also leave, the ratio becomes 1 : 5. Originally the number of girls in the group was**

**2.The area of the largest triangle, that can be inscribed in a semicircle of radius r cm is**

**3. 12 persons can do a piece of work in 4 days. How many persons are required to complete 8 times the work in half the time?**

**4. Two pipes can fill a tank in 15 hours and 20 hours respectively, while the third can empty it in 30 hours. If all the pipes are opened simultaneously, the empty tank will be filled in**

**5.The difference between the interior and exterior angles of a regular polygon is 60. The number of sides in the polygon is :**

**6. A Person bought some articles at the rate of 5 per rupee and the same number at the rate of 4 per rupee. He mixed both the types and sold at the rate of 9 for 2 rupees. In this business he suffered a loss of Rs. 3. The total number of articles bought by him was**

**7. A and B can do a work in 45 days and 40 days respectively. They began the work together but A left after some time and B completed the remaining work in 23 days. After how many days of the start of the work did A leave?**

**8. An individual pays 30% income tax. On this tax he has to pay a surcharge of 10%. Thus, the net tax rate, he has to pay, is**

**9. If the price of tea is increased by 20%, by how much per cent the consumption of tea be reduced so that there is no increase in the expenditure on it?**

**10.The principal, which will amount to Rs. 270.40 in 2 years at the rate of 4% per annum compound interest, is**

**Answers and Solution:**

1. (3)

let the original number of boys and girls be x and y respectively

then

x/y-15 = 2/1

=> x = 2y-30

Again, (x-45)/(y-15) = 1/5

=> 5x – 225 = y-15

after solve we get

so y = 40

2.(2)

3. (1)

12 persons can complete a work in 4 days.

=> 24 persons can complete the work in 2 days.

=> 24 persons can complete the 8 times work in 16 days.

=> 24*8 persons = 192 persons can complete.

4.(2)

part of tank filled in 1 hour when all three pipe are opened simultaneously

= 1/15 + 1/20 – 1/30 = 1/12

Hence, the tank will be filled in 12 hours

5.(3)

6. (2)

let the person buy 10 articles.

Total CP = Rs.(1+5/4) = Rs.9/4

SP of 10 articles

= Rs. 2/9 *10 = Rs.20/9

so Loss = (9/4 – 20/9)= 1/36

Now, if loss is Rs.1/36 ,number of article = 10

so If loss is Rs.3 ,number of article = 36*10*3 = 1080

7. (2)

8. (3)

The net tax rate = (30+30*10/100)% = 33%

9. (3)

10. (3)

let the principal be Rs. p

so 270.40= p(1+4/100)^2

p = Rs.250