**Type A, 12 kg of rice worth Rs. 40/kg is mixed with Type B, rice worth Rs. 24/kg. What should be the quantity of Type B rice, if the mixture is sold at Rs. 45/kg with 25% profit added in it?**- 18
- 48
- 4
- Cant Say

Answer: Option C.

C.P. of the mixture = 45/1.25 = Rs. 36/kg..

So, (40-36)/(36-24) = (N)/(12) ⇒ N = 4 Kg.

**A person spends 1/7th of his salary on travel,1/3rd of the remaining on food, he then spends 1/4th of the remaining on rent. Finally he puts 1/6th of the remaining as a monthly savings, after which he has 25000 left. What is his salary (in Rs.)?**- 70 K
- 14 K
- 84 K
- 26 K

Answer: Option A.

Let M be the total salary

Therefore, as per question, M × (6/7) × (2/3) × (3/4) × (5/6) = Rs 25000

M = Rs 70000**Point C(x,y) divides the distance AB with point A(8,12) and point B(16, 18) in a ratio of 3:5, with AC being shorter than BC. What are the co-ordinates of C?**- (12,15)
- (14.5, 12.5)
- (11,14.25)
- (8.3, 45)

Answer: Option C.

x co-ordinate of C = [(5×8) + (3×16)] / (3+5) = 11

y co-ordinate of C = [(5×12) + (3×18)] / (3+5) = 14.25

Co-ordinates of C is ( 11, 14.25 )**How many terms of the sequence -12, -8, -4,…so on, to make a sum of 120?**- 11
- 12
- 10
- 13

Answer: Option B.

The series is in A.P. where a = -12 and d = 4.

So 120 = (n/2)[2 × (-12) + (n -1) × 4].

On solving this, we get n = 12**A TV set listed at Rs 3200 is sold to a retailer at a successive discount of 25% and 15%. The retailer desires a profit of 20%, after allowing a discount of 10% to the customer. At what price should he list the TV set (in Rs.)?**- 2720
- 2448
- 2448
- 2133

Answer: Option A.

The retailers C.P. = 3200 × 0.75 × 0.85 = Rs 2040.

His expected S.P. = 2040 × 1.2 = Rs 2448.

But S.P. is 90% of the L.P., as there is a discount of 10%.

So L.P. = 2448/0.9 = Rs 2720Coal India Preparation Links- Sample Aptitude Questions of Coal India
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**What is the average of the first 100 odd natural numbers?**- 100.5
- 125
- 50
- 100

Answer: Option D.

As we know, sum of first n odd numbers is n^{2}

Therefore, sum of 1st 100 odd numbers is 100^{2}and average will be 100^{2}/100 = 100.**A, B and C invested capitals in the ratio 2 : 3 : 5, the timing of their investment being in the ratio 9 : 5 : 6. The profit if any will be distributed in the ratio**- 1:2:3
- 11:8:11
- 7:2;1
- 6:5:10

Answer: Option D.

Ratio of capitals = 2 : 3 : 5 and that of time = 9 :5: 6

Therefore, ratio of profits = 2 × 9 : 3 × 5 : 5 × 6 = 18 : 15 : 30 or 6 : 5 : 10**It takes 5 sec. for a clock to strike at 5’o clock. If the striking intervals are uniform how much time will it take to strike 9’o clock (in sec.)?**- 9
- 10
- 11
- 12

Answer: Option B

There are 4 intervals in 5 strokes.

Time taken to strike 1 stroke will be 5/4 sec.

At 9, there will be 9 strokes and 8 intervals between two strokes.

Thus time required = 5/4 × 8 = 10 sec**From the top of the Tower which is 240m high, if the angle of depression of a point on the ground is 30°, then the distance of the point from the foot of the Tower is <**- 40√3
- 80√3
- 120√3
- 240√3

Answer: Option D.

**In the inequality, x**^{2}- 14x + 50 < 5, find the range of x.- 5 > x > 9
- 5 < x < 9
- -5 < x < 9
- -5 > x > -9

Answer: Option B.

x^{2}- 14x + 50 < 5 ? (x-9)(x-5)<0

Now, here 2 cases arises

Case 1: (x-9)<0 & (x-5)>0

So we get range to be 5 < x < 9

Case 2: (x-9)>0 & (x-5)<0

Which gives x > 9 and x < 5 which cannot occur simultaneously, hence rejected.