A and B go by Bus from X to Z which is on the way to Y. C goes from Y to Z by Auto. A and B's Bus goes at 75km/hr and C's auto moves at 15km/hr. All the three start at 6:00am. After travelling some distance, B sees another friend D going by Cycle at 25km/hr to Z. B and A go ahead, meet C and pick him up. They return immediately to Z at the same time. The distance between X and Y is 600km and XZ is 400km.
Answer: C
X...............Z.............V...................YXZ= 400, ZV= 100 and VY = 100A and B's speed is 5 times C's speed.Starting from X they cover 500 km and starting from Y, C covers 100 km by the time they meet at V.A,B and C then cover 100 km to come to Z. (XZ= 400 km)A(as well as B) covers (500+100) = 600 km, taking 8 hours at their speed of 75 km/hr.
Answer: D
X...............Z.............V...................Y
XZ= 400, ZV= 100 and VY = 100
A and B's speed is 5 times C's speed.
Starting from X they cover 500 km and starting from Y, C covers 100 km by the time they meet at V.
A,B and C then cover 100 km to come to Z. (XZ= 400 km)
A(as well as B) covers (500+100) = 600 km, taking 8 hours at their speed of 75 km/hr.
Q. No. 2:
The speed of a bus during the second hour of its journey is twice that in the first hour. Also, its speed during the third hour is two-third the sum of its speeds in the first two hours. Had the bus travelled for three hours at the speed of the first hour, it would have travelled 120 km less. Find the average speed of the bus for the first three hours.
Answer: D Let the speed for the first hour be 's' kmph. Speed during second hour = 2s kmph. And speed in the third hour = 2/3 * (3s) = 2s kmph Distance travelled = 5s km Had it travelled at s kmph, distance travelled would have been equal to 3s kmph. Given, 5s -3s = 120 => s =60 Average speed for the first three hours = 5s/3 = 100 kmph.
Q. No. 3:
In a 500m race Dishu beats Abhishek by 100m or 5 seconds. In another race on the same track at the same speeds. Abhishek and Prashant start at one end while Dishu starts at the opposite end. How many metres would Abhishek have covered, by the time Dishu meets Prashant given that Dishu's speed is 10 m/sec more than that of Prashant.
Answer: C Abhishek's speed = 100/5 = 20 m/s Time taken by Abhishek to cover 500m = 500/20 = 25 seconds. Dishu's speed = 500/20 or 25 m/s. Prashant's speed = 15 m/s. Time taken by Dishu to meet Prashant in 500m race in opposite direction => 500/(15+25) = 12.5 seconds. Distance covered by Abhishek = 12.5(20) = 250 m.
Q. No. 4:
A ball is thrown twice from a place with the gap of 34 minutes between the two shots. A person approaching this point in a bus heard the second shot 33 minutes after he heard the the first shot. What is the speed of bus (in kmph) if sound travels at 330 m/s?
Answer: C Actual time between the two shots being fired = 34 minutes. If the man was stationary he would have heard the shots after 34 minutes. But since the car was moving towards the source, he heard the second shot after only 33 minutes = Distance travelled by the sound in 1 min. The Bus's speed = 1/33 *(Speed of sound) = 330m/s/33 = 10m/s => 36 kmph.
Q. No. 5:
P beats Q by 5 seconds in a race of 1000m and Q beats R by 5 metres in a race of 100m. By how many seconds does P beats R in a race of 1000m?
Answer: D If P takes t seconds to run 1000m, then Q takes (t+5) sec. In (t+5) sec Q runs 100m whereas R runs only 950m. R runs 1000m in 1000/950 * (t+5) sec. P takes t seconds to cover 1000m , while R takes (20t/19 + 100/95) sec. From the data given, we cannot determine t.
Q. No. 6:
Starting from my office, I reach the house 20 min late if I walk at 3kmph. Instead, if I walk at 4kmph, I reach the house 15 min early. How far is my house from my office?
Answer: C Let the distance between the office and the house be 1km Time required at 3kmph = 1/3 hr = 20 min. Time required at 4kmph = 1/4 hr = 15 min. Difference = 20-15 = 5min. Actual difference in timings = 20+15 = 35 min If difference is 5 min, distance is 1 km If difference is 35 min, distance is 7km.