General Questions
Practice and master this topic with our carefully crafted questions.
Relative speed = (2 + 3) = 5 rounds per hour.
So, they cross each other 5 times in an hour and 2 times in half an hour.
Hence, they cross each other 7 times before 9.30 a.m.
Suppose the thief is overtaken x hrs after 2.30 p.m.
Then, distance covered by the thief in x hrs
= distance covered by the owner in (x - 1/2) hrs.
∴ 60x = 75 (x - 1/2) <=> 15x = 75/2
<=> x = 5/2 hrs.
So, the thief is overtaken at 5 p.m.
Suppose they meet x hrs after 8 a.m.
Then,
(Distance moved by first in x hrs) +
[ Distance moved by second in ( x-1) hrs ]
= 330
∴ 60x + 75 (x-1) = 330
=> x = 3
So, they meet at (8 + 3 )
i.e. 11 a.m.
Let distance covered by dog in 1 leap is x and
Distance covered by cat in 1 leap is y
Then, 3x = 4y
∴ x= 4/3y
Now, Ratio of speed of dog and cat = Ratio of distance covered by them in the same time = 4x : 5y
= 16/3y : 5y
= 16 : 15
At the time of meeting, let the distance travelled by the the second train be x km.
Then, distance covered by the first train is (x + 100) km.
∴ x /40 = (x + 100) /50
<=> 50x = 40x + 4000
<=> x = 400.
So distance between P and Q = (x + x + 100) km
= 900 km.
Suppose they meet x hours after 14.30 hrs.
Then, 60x = 80 (x - 2)
or x = 8
∴ Required distance = (60 X 8) km = 480 km.
In the same time, they cover 110 km and 90 km respectively.
∴ Ratio of their speeds = 110 : 90 = 11 : 9
Ratio of speed = 3 : 4.
Ratio of times taken = 4 : 3.
Suppose A takes 4x hrs and B takes 3x hrs to reach the destination.
Then, 4x - 3x = 30/60 = 1/2
or x = 1/2
∴ Time taken by A = 4x hrs = 4 X hrs = 2 hrs.
Average speed = [(2 X 3 X 2) / (3 + 2) = 12/5 km/hr.
Distance travelled = (12 /5 X 5) km = 12 km.
∴ Distance between house and school :
= 12/2 km = 6 km.
Let A's speed = x km / hr.
Then, B's speed = (7 - x) km / hr.
So, 24/x + [2 4 / (7 - x ) ] = 14
<=> 24 (7 - x) + 24x = 14x (7 - x)
<=> 14x2 - 98x + 168 = 0
<=> X2 – 7x + 12 = 0
<=> (x - 3) (x - 4) = 0
<=> x = 3 or x = 4.
Since, A is faster than B, so A's speed = 4 km / hr
and B's speed = 3 km / hr.