# UPSC IAS Exam: IAS Prelims CSAT Basic Numeracy Set 7

In the Civil Services IAS Prelim Examination, the CSAT paper has been made qualifying in nature from 2015 onwards. The candidates have to score at least qualifying marks in the paper but in case, if a candidate could not be able to score the required qualifying marks in CSAT Paper then his/her other papers will not be evaluated. So, it is important for the candidates to do preparation in such a manner that there must not lay them in any suspicion of underscoring.

**1.In an examination it is required to get 46% of the aggregate marks to pass. A student gets 301 marks and is declared failed by 3% marks. What are the maximum aggregate marks a student can get?**

a) 700

b) 725

c) 745

d) 765

**Answer (a)**

** Explanation:**

**2.When a car manufacturer reduced its selling price by 50%, the number of cars sold radically increased by 600%. Initially the manufacturer was getting only 140% profit. What is the percentage increase of his total profit?**

a) 10%

b) 14%

c) 12%

d) 0%

**Answer (d) **

**Explanation:**

**Category: Ratio and proportion**

** 3.One year ago the ratio between A’s and B's salary was 3:4. The ratio's of their individual salaries between previous year's and present year's salaries are 4:5 and 2:3 respectively. At present the total of their salary is Rs.8580. The salary of A now is :**

a) Rs.3800

b) Rs.3300

c) Rs.3900

d) Rs.3120**Answer (b)**

** Explanation: **

**4.The product of two natural numbers in the ratio 3:5 is 2535. What is the largest number?**

a) 39

b) 64

c) 65

d) 66**Answer (c)**

** Explanation:**

**Category: HCF and LCM**

**5.A rectangular courtyard 15 meters 17 cms long 9 meters and 2 cms wide is to be paved exactly with square tiles, all of the same size. What is the largest size of the tile which could be used for the purpose? **

a) 14

b) 21

c) 42

d) 41

**Answer (d) **

**Explanation: **

Size of each tile = HCF of 1517 and 902.

= 41 cm2.

Category: Mixture and Alligation

**6.A burette contains 30ml mixture of chlorine and water in ratio 7:3. How much water should be added to this mixture so that the percentage of water in the mixture becomes 40%? **

a) 2.3 ml

b) 3.5 ml

c) 4.1 ml

d) 5.0 ml

**Answer (d)**

** Explanation: **

**7.Milkman purchases milk for Rs 3.75 and after adding some quantity of water sells it at Rs 5 and gets a profit of 60%. What is the ratio of milk to water a customer receives?**

a) 1:5

b) 1:4

c )5:1

d) 4:1

**Answer (c) **

**Explanation:**

**Category: Clock**

**8.At how many points between 12 O'clock and 1 O'clock are the minute hand and hour hand of a clock at an angle of 30 degrees to each other?**

a) 2

b) 4

c) 1

d) 3

**Answer (c)**

** Explanation:**

Between 12 and 1, the minute hand and hour hand are at an angle of 30o to each at around 12:06 PM and the next time they will be at angle of 30o to each other will be at 1 PM.

Category: Time and Work

**9.An inlet pipe fills water in a reservoir at the rates of 0.1 litres/sec. When the reservoir is full, the inlet is opened but due to a leak at the bottom, it is emptied in 12 hours. What is the capacity of the reservoir, if it is known that the leak can empty the full reservoir in 8 hours had there been no inlet?**

a) 7500

b) 7690

c) 8400

d) 8640

**Answer (d) **

**Explanation: **

**10.Ram works twice as fast as Shyam. If Shyam can complete a work in 40 days independently, the number of days in which Ram and Shyam can together finish the work is :**

a) 14.5 days

b) 6.67 days

c) 13.33 days

d) 15 days

**Answer (c)**

**Explanation:**

Shyam can complete the work in 40 days, so Ram can finish the work in 20 days.

Together = 1/40 + 1/20 =3/40

Ram & Shyam together take 40/3 = 13.33 days to finish the work.