The most important section in the clerk written exam in which most of the candidates struggle a lot is **Maths**. Since the syllabus is vast there is lot to study. The maths section carries 10 questions out of 25 that are asked in first part. All those candidates who are preparing for the** clerk post** should know that, it is important to practice maths daily along with the previous year paper and sample paper. With regular practice and hard work you can achieve anything.

Here we are with some important questions of maths with full explanation that have been collected from previous year paper. Now, you can give this** online** **test** of Maths and prepare yourself for the written exam. All the questions that are mentioned below are selected from exam point of view.

Along with maths you can also practice for Indian Army Clerk Online Test of General Science

**Q 1.**The product of two numbers is 216 and their HCF is 3, what is their LCM?

- 648
**72**
- 219
- 231
- Answer is: 72

**Answer** With Explanation
- We have given, product of two numbers= 216. HCF of two numbers= 3. We know that, LCM×HCF = Product of two numbers

LCM×3 = 216

LCM = 216/3

LCM = 72

**Q 2.**A man buys a toy for Rs.100 and sells it for Rs.150. Then his gain percent is

**50%**
- 60%
- 30%
- 40%
- Answer is: 50%

**Answer** With Explanation
- Cost price of toy(CP) = Rs 100

Selling price of toy(SP) = Rs 150

Profit % = (SP-CP/CP)×100

= (150-100/100)×100

= 50%

**Q 3.**In how many years will Rs.7500 double at 8% simple interest?

- 12
- 8
**12.5**
- 10
- Answer is: 12.5

**Answer** With Explanation
- Principal = Rs 7500

Rate% = 8

Let the total amount be = A (where A = P+I)

Let in X years A = 2P

Now, 2P-P = P×R×T/100

P = P×R×X/100

X = 100/R

X = 100/8

X = 12.5

**Q 4.**Express 63 km/h into m/s

- 16.5
**17.5**
- 18.5
- 19.5
- Answer is: 17.5 m/sec

**Answer** With Explanation
- 1 Km = 100 m

1 hr = 3600 sec

Hence, 63 km/hr = (63×1000/3600)m/sec

= 63×5/18

= 17.5 m/sec

**Q 5.**A fruit seller had some apples.He sells 40% apples and still has 420 apples.How many apples he had originally?

- 600
- 650
- 700
**750**
- Answer is: 750

**Answer** With Explanation
- Let the actual number of apples be = a

Now, he sold 40% of apples and are left with 420.

a-(40/100)×a = 420

100a-40a/100 = 420

60a = 42000

a = 42000/60

a= 700

**Q 6.**If 2994/14.5 = 172, then 29.94/1.45 =?

- 172
**17.2**
- 1.72
- 0.172
- Answer is: 17.2

**Answer** With Explanation
- We have given that, 2994/14.5 = 172

(2994/14.5 × 1/10) = 172/10

(29.94/1.45) = 17.2

**Q 7.**The angle of elevation of a ladder leaning against a wall is〖60〗^0 and the foot of the ladder is 4.6m away from the wall. The length of the ladder is

- 4.6
**9.2**
- 10
- 11.2
- Answer is: 9.2

**Answer** With Explanation
- Angle of elevation = 60°

Distance between wall and foot off ladder = 4.6

Let the length of ladder be = H

cos 60° = 4.6/H

1/2 = 4.6/H

H = 4.6×2

H = 9.2 m

**Q 8.**The average of 20 values is 18. If 3 is subtracted from each of the value, then the new average will be

- 21
**15**
- 16
- 17
- Answer is: 15

**Answer** With Explanation
- Let the sum of 20 values be = a

then, a/20 = 18

a= 20×18

a= 360

Now, 3 is subtracted from each values. So, total values subtracted from the sum is = 20×3= 60

Remaining value= 360-60 => 300

New average = 300/20 => 15

**Q 9.**The length of a tunnel, which a train 90 m long, travelling at 48 km/h, can cross in 21 s is

- 180
- 280
**190**
- 290
- Answer is: 190m

**Answer** With Explanation
- Length of train = 90 m

Speed of train = 48 km/hr

= 48×1000/3600

= 240/18 m/sec

Time taken by the train = 21 sec

Let length of platform = A

Length of platform+length of train = speed of train×time taken

A+90 = (240/18)×21

90+A = 280

A = 190 m

**Q 10.**What percentage is 390 g of 1 kg 500 g?

**26**
- 20
- 22
- 25
- Answer is: 26

**Answer** With Explanation
- 1 kg 500 g = 1000 g + 500 g => 1500 g

(390/1500)×100

390/15 = 26%