exam Maths Puzzle

Rajesh walks to and fro to a shopping mall. He spends 30 minutes shopping. If he walks at speed of 10 km an hour, he returns to home at 19.00 hours. If he walks at 15 km an hour, he returns to home at 18.30 hours. How fast must he walk in order to return at 18.15 hours?

A.

17 km/hr

B.

18 km/hr

C.

19 km/hr

D.

20 km/hr

Read Solution (Total 1)

As per the question, let D be the total distance and ‘t’ is the time taken.

So we have:

D=10t=15(t−0.5)
⇒t=1.5 hrs

$⇒D=15 km

Now, for the condition given we have:

15=S(t−34)

where ‘S’ is the required speed.

⇒S(32−34)=15

⇒S = 20 km/hr
5 years agoHelpfull: Yes(0) No(0)

exam Other Question

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.

2.

Common data question: 1/2

What is the total distance travelled by A?

A.

480 km

B.

450 km

C.

550 km

D.

600 km 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 1000 m?

A.

5 sec

B.

7 sec

C.

10 sec

D.

Cannot be determined