1
Question
One day Prakash started late for office by 1 hour, so he increased his normal speed by 5 km/hr so that he reaches on time. Find the normal time taken to reach his office if his office is at a distance of 60 km from his house.
One day Prakash started late for office by 1 hour, so he increased his normal speed by 5 km/hr so that he reaches on time. Find the normal time taken to reach his office if his office is at a distance of 60 km from his house.
Open in App
Solution
The correct option is D 4 hrs
Take a middle answer option, say 5 hours
Normal speed = 60/5 = 12 kmph
Speed increased to 12 + 5 = 18 kmph.
60/18 = 3.33 hours, the difference is more than 1 hour. This is not the answer.
We can also eliminate 6 hours, as that will result in a higher time difference.
Answer is either 3 or 4 hours (answer is close to 5)
Trying for 4 hours,
Normal speed = 60/4 = 15 kmph
Speed increased to 20 kmph
60/20 = 3. 4 – 3 = 1. This is the answer. Option (d)
4 hrs
Take a middle answer option, say 5 hours
Normal speed = 60/5 = 12 kmph
Speed increased to 12 + 5 = 18 kmph.
60/18 = 3.33 hours, the difference is more than 1 hour. This is not the answer.
We can also eliminate 6 hours, as that will result in a higher time difference.
Answer is either 3 or 4 hours (answer is close to 5)
Trying for 4 hours,
Normal speed = 60/4 = 15 kmph
Speed increased to 20 kmph
60/20 = 3. 4 – 3 = 1. This is the answer. Option (d)
Suggest Corrections
0
Similar questions
View More
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program
