practice questions to ace the si exam
తెలంగాణలో పోలీసు కొలువులను భర్తీ చేసేందుకు నోటిఫికేషన్ వెలువడింది. పెద్ద సంఖ్యలో ఉద్యోగాలను భర్తీ చేసేందుకు పోలీస్ రిక్రూట్మెంట్ బోర్డ్ భారీ కసరత్తు చేస్తున్నది. పోలీసు ఉద్యోగానికి ఈజీగా ఎంపికయ్యేందుకు ‘నిపుణ’ కథనాలను అందిస్తున్నది.
This article is in continuation to the last article on preparation for the Sub-Inspector of Police recruitment exam. Here are some practice questions and solutions on the Time and Distance topic.
1. A person travelled 1440 km in 20 hours. Find his speed.
Solution:
S = 1440 / 20 = 72 km/hr
Two options are there in m/s, so convert speed from km/hr to m/s
S = 72 × 5/18 = 20 m/s
2. In covering a distance of 240 km, Sunil takes 3 hours more than Madhu. If Sunil doubles his speed, then he would take 1 hour less than Madhu. Then find the speed of Sunil.
Solution:
Let Sunil’s speed = x km/hr
Then 240/x – 240/2x = 4
=> 240/2x = 4
=> 120/x = 4
=> x = 30
Therefore, speed of Sunil
= 30 km/hr
3. Robert is travelling on his cycle and has calculated to reach point A at 2 pm, if he travels at 10 kmph. He will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 pm?
Solution:
Let the distance = x km
So x/10 – x/15 = 2
=> (3x-2x)/30 = 2
=> x = 60 km
Time taken to travel 60 km at 10 km/hr = 60/ 10 = 6 hours
So, Robert started 6 hours before 2 pm, i.e., at 8 am
He should reach at 1 pm means, the time will be 5 hours
Therefore, the required speed
= 60/5 = 12 km/hr
4. A person travelled a distance of 92 km in 10 hours. He travelled partly on foot at 5 km/hr and partly on bicycle at 12 km/hr. Then find the distance travelled on foot?
Solution:
Let the distance travelled on foot be ‘x’ km.
Then, distance travelled on bicycle = (92 -x) km.
So x/5 + 92 -x/12 = 10
12x + 460 – 5x = 600
7x = 140
x = 20
=> the distance travelled on foot = 20 km.
5. By travelling at 40 kmph, a person reaches his destination on time. He covered two-third of the total distance in one-third of the total time. What speed should he maintain for the remaining distance to reach his destination on time?
Solution:
Speed = 40 km/hr
Let Time
= x hrs
So Distance
= 40x km
Covered Distance
= 2/3 × 40x = (80x/3)km
Covered Time = x/3 hrs
Remaining Distance =
40x – 80x/3 = (40x/3) km
Remaining Time = 2x/3hrs
Required Speed =
40x/3 × 3/2x = 20 km/hr
6. A boy travelled from his house to school at 3 km/hr, and he reaches 9 minutes late. Next day, he travelled at 4 km/hr, and he reaches 6 minutes early. Then find
the distance between house and school?
Solution:
Let Distance = x km
If the boy reaches the school on time, the time taken = x minutes
First day journey time = (x + 9) minutes
Second day journey time =
(x – 6) minutes
Difference between two days Journey time = (x + 9) – (x – 6) = 15 min = ¼ hours
So x/3 – x/4 = 1/4
x = 3 km
7. A man decided to cover a distance of 6 km in 84 minutes. He decided to cover two-thirds of the distance at 4 km/hr and the remaining at some different speed. Find the speed after the two-third distance has been covered.
Solution:
Distance = 6 km
Time = 84 min
2/3 of Distance
= 2/3 × 6 = 4 km,
Speed = 4 km/hr
Time = 4/4 = 1 hour
= 60 minutes
So remaining time
= 84 – 60 = 24 minutes = 24/60 = 2/5 hours
Remaining distance = 6 – 4 = 2 km
The required speed
= 2 × 5/2 = 5 km/hr
