- A boat can cover 21 km upstream and 60 km downstream in 9 hours. The speed of the boat in still water is 4 km/hr more than the speed of the stream. Find the time taken by the boat to cover 55 km upstream and 140 km downstream.
18 hours 10 minutes20 hours 40 minutes15 hours 20 minutes28 hours 20 minutes22 hours 30 minutesOption E

Let the speed of the stream be x km/hr.

Speed of the boat in still water = x + 4 km/hr.

21/(x+4-x)+60/(x+4+x) = 9

=> x = 6

Upstream speed = 4 km/hr.

Downstream speed = 16 km/hr.

Required time = 55/4 + 140/16 = 22

hours 30 minutes - Area of the circular field is equal to the area of the rectangular field. Length of the rectangular field is 9 m more than the breadth of the rectangular field. Find the perimeter of the rectangular field, if the circumference of the circular field is 132 m.
95 m110 m80 m150 m100 mOption D

Let the length of the rectangular field be x m.

Breath = (x-9) m

Radius = 132/2*pi = 21 m

Area of the circular filed = 22/7*21*21 = 1386 m^2

Area of the rectangular field = x(x-9) = 1386

=> x^2 – 9x – 1386 = 0

=> x^2 – 42x + 33x – 1386 = 0

=> x = 42, – 33

Perimeter = 2*(42+33) = 150 m - Puja invested Rs.10,000 in a scheme offering 20% compound interest compounded annually for three years. Rohit invested Rs.12000 in another scheme offering 25% compound interest for2 years. Find the difference between the interests earned by Puja and Rohit.
Rs.530Rs.480Rs.510Rs.500Rs.400Option A

Interest earned by Puja = 10000*{(1+0.20)^3 – 1} = Rs.7280

Interest earned by Rohit = 12000*{(1+0.25)^2 – 1} = Rs.6750

Required difference = 7280 – 6750 = Rs.530 - Puja invested Rs.10,000 in a scheme offering 20% compound interest compounded annually for three years. Rohit invested Rs.12000 in another scheme offering 25% compound interest for2 years. Find the difference between the interests earned by Puja and Rohit.

40Either 15 or 35355015Option B

Interest earned by Puja = 10000*{(1+0.20)^3 – 1} = Rs.7280

Interest earned by Rohit = 12000*{(1+0.25)^2 – 1} = Rs.6750

Required difference = 7280 – 6750 = Rs.530

- A bag contains 50 bulbs, out of which certain number of bulbs are defective. Two bulbs are randomly drawn from the bag and the probability that a defective bulb and non-defective bulb are drawn is 3/7. Find the number of defective bulbs in the bag.
40Either 15 or 35355015Option B

Let the number of defective bulbs be x.

And the number of non-defective bulbs = (50-x)

Probability that a defective and a non-defective bulb are drawn = (xC1*(50-x)C1)/50C2 = 3/7 x^2 – 50x + 525 = 0

=> x^2 -35x – 15x + 525 = 0

=> x = 35,15

Either 15 or 35 - How many four-letters words having at-least one vowel can be formed by using the letters of the word ‘BAKESHOP’?
12501320156016601490Option C

Total number of ways in which letters are selected

= 3C1*5C3 + 3C2*5C2 + 3C3*5C1 = 30+30+5 = 65

Four letters are arranged within the word = 4! = 24 ways

Total number of words formed = 24*65 = 1560 - 17,36,91,188,321,492
173691492321Option C

+19*1

+19*3

+19*5

+19*7

+19*9

93 should be in place of 91. - 21,27,52,116,197,231
522127116231Option E

+6^1

+5^2

+4^3

+3^4

+2^5

229 should be in place of 231. - 9,11,15,24,54,177
5417791124Option A

+1!+1

+2!+2

+3!+3

+4!+4

+5!+5

52 should be in place of 54. - 15,14,24,63,236,1175
142415117563Option D

*1-1^2

*2-2^2

*3-3^2

*4-4^2

*5-5^2

1155 should be in place of 1175.

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Directions(6-10): **Find out the odd one out from the following series.