A boat takes a total time of twelve hours to travel 105 kms upstream and the same distance downstream. The speed of the boat in still water is six times of the speed of the current. What is the speed of the boat in still water? (In km/hr)
12
30
18
24
36
Answer: Option C.
Let ‘x’ be the speed of Boat in still water, and ‘y’ be the speed of current.
Then, according to the question,
Speed of the boat in still water = 6 speed of current
x = 6y
Also given that ,
105/(x+y) +105/(x-y) =12
105/7y +105/5y =12
12y=36
y=3
Therefore, x= 6×3=18
Speed of the boat in still water= 18kmph
At 60% of its usual speed, a train of length L meters crosses platform 240 meters long in 15 seconds. At its usual speed, the train crosses a pole in 6 seconds. What is the value of L (in meters)?
440
425
220
480
240
Answer: Option D.
Let usual speed = S m/s.
According to the question,
60% of S= (L+240)/15
9S= L+240………… (i)
Also given that, S = L/6
L = 6S …. (ii)
From (i) & (ii)
9S= 6S+240
3S= 240
S=80 m/s
From (ii)
L= 6×80 =480 m
P, Q and R have a certain amount of money with themselves. Q has 50% more than what P has, and R has 1/3rd of
75
60
120
80
90
Answer: Option D.
Assume that P has 2x amount.
Therefore, Q = 3x amount (50% more than P)
And R = 3x × 1/3 = x
Ratio of P : Q : R = 2x : 3x : x = 2 : 3 : 1
Thus, P alone have = (2/6) × 240 = Rs. 80
Suri gave 25% of her monthly salary to her mother. From the remaining salary, she paid 15% towards rent and 25%, she kept aside for her monthly expenses. The remaining amount she kept in bank account. The sum of the amount she kept in bank and that she gave to her mother was Rs. 42000. What was her monthly salary?
Rs. 50,000
Rs. 60,000
Rs. 65,000
Rs. 64,000
Rs. 72,000
Answer: Option B.
Let x be the total income
(75/100*60/100)x + 25/100x = 42000
Solving, x = 60000
At present, Ami’s age is twice Dio’s age and Cami is two years older than Ami. Two years ago, the respective ratio between Dio’s age at that time and Cami’s age at that time was 4: 9. What will be Ami’s age four years hence?
40 years
30 years
42 years
36 years
48 years
Answer: Option A
D; A = 2D; C = A+2 = 2D+2
Given, D-2/(2D+2)-2 = 4/9
Solving, D = 18 Years and A = 36+4 = 40 years.
A vertical stick 12 cm long casts a shadow 8 cm long on the ground. At the same time, a tower casts a shadow 40m long on the ground. The height of the tower is
65m
70m
72m
60m
Answer: Option D.
height of Tower/Length Of Stick
=Length of shadow of Tower/Length of shadow of Stick
h/12=40/8
h=40*12/8 = 60 metre
40.1% of 360.2 + 58.98% of ? = 150
10
20
30
40
50
Answer: Option A.
40*360+59%of X=150
144+59%of X=150
X=10(approx)
