Question: 21 -
A farmer travelled from his village to city to buy seeds. He went by bicycle at a speed of 20 km/hr and came back at a speed of 5 km/hr. If the farmer took 5 hours and 40 minutes to complete his journey, find the distance between village and city?
-
15 km
-
23 km
-
25 km
-
19 km
Answer:
19 km
Solution:
Total distance travelled = Average speed * Total time taken to complete the journey
Average speed =
Total time taken = 4 hour 45 minutes =285⁄60 =19⁄4hour
So, Total distance travelled = 8 *19⁄4= 38 km
Distance between village and city will be half of the total distance travelled:
So, distance between village and city =38⁄2 = 19 km
Total distance travelled = Average speed * Total time taken to complete the journey
Average speed =
Total time taken = 4 hour 45 minutes =285⁄60 =19⁄4hour
So, Total distance travelled = 8 *19⁄4= 38 km
Distance between village and city will be half of the total distance travelled:
So, distance between village and city =38⁄2 = 19 km
Question: 22 -
A man goes to his office at 2⁄3 of the speed at which he returns from the office. If his average speed is during the whole journey is 24 km/hr, at what speed the man goes to office?
-
20 km/hr
-
22 km/hr
-
23 km/hr
-
21 km/hr
Answer:
20 km/hr
Solution:
Let the speed of man when he returns from office = X
So, his speed when he goes to office =2⁄3X
Average speed =
Speed at which he goes to office is 2⁄3 of X,So it will be 2⁄3*30=20 km/hr
Let the speed of man when he returns from office = X
So, his speed when he goes to office =2⁄3X
Average speed =
Speed at which he goes to office is 2⁄3 of X,So it will be 2⁄3*30=20 km/hr
Question: 23 -
The ratio between the speeds of two cars is 5:8. If the first car covers 200 km in 2 hours, find the speed of the second car.
-
150 km/hr
-
160 km/hr
-
140 km/hr
-
170 km/hr
Answer:
160 km/hr
Solution:
Let the speed of two cars is 5X and 8X.
=200⁄2= 100 km/hr
Therefore, 5X = 100
X =100⁄5 = 20 km/hr
So the speed of second car will be = 8 * 20 = 160 km/hr
Let the speed of two cars is 5X and 8X.
=200⁄2= 100 km/hr
Therefore, 5X = 100
X =100⁄5 = 20 km/hr
So the speed of second car will be = 8 * 20 = 160 km/hr
Question: 24 -
A man covers a distance of 110 km between two cities in 10 hours. He travelled partly on foot at 9 km/hr and partly on a bicycle at 15 km/hr. Find the distance travelled on foot.
-
92 km
-
94 km
-
60 km
-
96 km
Answer:
60 km
Solution:
Let the distance travelled on foot = X km
,, the distance travelled on bicycle would be = (90 - X) km
Total time taken to cover the distance = 10 hrs
Time taken to cover the 110 km would be equal to the sum of the time taken to cover the distances partly on foot and partly on bicycle.
So,X⁄9+110-X⁄15= 10
5X + 3(110 -X) = 45 * 10
5X + 330 - 3X = 450
2X =450 - 330
2X = 120
X =120⁄2= 60 km
Let the distance travelled on foot = X km
,, the distance travelled on bicycle would be = (90 - X) km
Total time taken to cover the distance = 10 hrs
Time taken to cover the 110 km would be equal to the sum of the time taken to cover the distances partly on foot and partly on bicycle.
So,X⁄9+110-X⁄15= 10
5X + 3(110 -X) = 45 * 10
5X + 330 - 3X = 450
2X =450 - 330
2X = 120
X =120⁄2= 60 km
Question: 25 -
A man covers first 48 km of his journey in 40 minutes and next 32 km in 30 minutes. Find his average speed.
-
67 km/hr
-
74 km/hr
-
64 km/hr
-
70 km/hr
Answer:
64 km/hr
Solution:
Total distance = 48 + 32 = 80 km
Total time = 40 + 35 = 75 minutes =75⁄60 hrs
Total distance = 48 + 32 = 80 km
Total time = 40 + 35 = 75 minutes =75⁄60 hrs