- Three pipes A, B and C are connected to a tank. A and B together can fill the tank in 10 hours, B and C together in 15 hours and C and A together in 12 hrs. In how much time all pipes fill the tank together ?
76849Option C

(A + B)’s 1 hour work = 1 /10

(B + C)’s 1 hour work = 1/ 15

(C + A)’s 1 hour work = 1/ 12

(A + B + C)’s hour work = 1/{ 2 [ 1/ 10 + 1/ 15 + 1/ 12]}

= 1/{ 2 [( 6 + 4 + 5) /60 ] }

= 1/8

(A + B + C) can do the required work in 8 hours. - Tea worth Rs. 126 per kg and Rs. 135 per kg are mixed with a third variety in the ratio 1 : 1 : 2. If the mixture is worth Rs. 153 per kg, then what is the price of third variety per kg.
178180.6155.6175.5181.8Option D

Let price of third variety was Rs. A per kg

Let respective amounts of these tea were x kg, x kg and 2x kg.

126x + 135x + 2Ax = 153 × 4x

⇒ 2A = 351

⇒ A = 175.5 rupee per kg - The height of a circular cylinder is increased to six times and the base area is decreased to oneninth of its value. The factor by which the lateral surface of the cylinder increase ?
12345Option B

Base area is decreased to one-ninth it means radius is decreased to one-third.

LSA is increased by [2𝜋× 𝑟/ 3 ×6ℎ ]/2𝜋𝑟ℎ = 2 times - What will be the ratio of petrol and kerosene in the final solution formed by mixing petrol and kerosene that are present in three same capacity of vessels in the ratio 4 : 1, 5 : 2 and 6 : 1 respectively ?
81 : 2687 : 2578 : 2983 : 2281 : 21Option D

P ==== K

A 4====1

B 5====2

C 6====1

In resultant mixture, the ratio of petrol and Kerosene

= (4 × 49 + 5 × 35 + 6 × 35) ∶ (1 × 49 + 2 × 35 + 1 × 35)

= 83 : 22 - A right cylindrical vessel is full of water. How many right cones having the same diameter and height as that of the right cylinder will be needed to store that water?
56348Option C

Volume of cylindrical vessel = πr²h

Volume of cone = 1/3 πr^ 2h

Number of cones = πr²h /(1 /3 πr^2h) = 3 - A car driver covers a distance between two cities at a speed of 60 kmph and on the return his speed is 40 kmph. He goes again from the 1st to the 2nd city at twice the original speed and returns at half the original return speed. Find his average speed for the entire journey.
5060704080Option D

Required average speed = 4/[ (1/60) + (1/40) + (1/120) + (1/20)] = 4×120/12 = 40 𝑘𝑚𝑝ℎ - Pankaj walked at 5 km/h for certain part of the journey and then he took an auto for the remaining part of the journey and travelling at 25 km/h. He took 10 hours for the entire journey, then find what part of journey did he travelled by auto if the average speed of the entire journey be 17 km/h.
150 km130 km110 km120 km100 kmOption A

Let time taken by Pankaj during walking be ‘t’ hours

5t + 25 [10 – t] = 17 × 10

⇒ 20t = 80

⇒ t = 4 hours

Part of journey travelled by auto = 25 × 6 = 150 km - While selling a watch, a shopkeeper gives a discount of 15%. If he gives a discount of 20%, he earns Rs 51 less as profit. What is the original price of the watch?
Rs. 1020Rs. 1100Rs. 1250Rs. 1020Rs. 1122Option D

Let marked price is Rs. 𝑥

𝑥 × 85/100 − 𝑥 × 80/100 = 51

⇒ 𝑥 × 5/100 = 51

⇒ 𝑥 = Rs. 1020 - A bus travels at 75 km/h without any stoppage. But due to stoppages at intermediate stands its average speed becomes 63 km/h. How much minute bus stop every hour?
6.8 min.5.7 min.8.8 min.7.5 min.9.6 min.Option E

Without stopping bus travels 75 km/hr.

With stop bus travels 63 km/hr.

Stopping time = 75 –63/75 = 0.16 hour

= 0.16 × 60 = 9.6 min. - Two trains running in opposite directions to each other, cross a man standing on the platform in 30 sec and 12 sec respectively and they cross each other in 20 seconds. Find the ratio of their speed.
8:95:71:22:34:5Option E

Let the speed of first train is x m/sec Speed of second train is y m/sec Length of first train = 30x

Length of second train = 12y

ATQ,

(30𝑥+12𝑦)/𝑥+𝑦 = 20

= 30x + 12y = 20x + 20y

10x = 8y

𝑥/ 𝑦 = 8/ 10

x: y = 4: 5