# Distance and Time Quiz Set 018

### Question 1

A boy walks along the three edges of an equilateral triangle at average speeds of 3 km/h, 9 km/h and 8 km/h. What is the average speed along the whole journey?

A

\$5{11/41}\$ kmph.

B

\$6{17/40}\$ kmph.

C

\$4{3/43}\$ kmph.

D

\$7{38/43}\$ kmph.

Soln.
Ans: a

Let the edge of the triangle be L. Total distance travelled = 3L. Time taken = \$L/3 + L/9 + L/8\$. So overall average speed = \${3L}/{L/3 + L/9 + L/8}\$ which simplifies to \${216/41}\$, which is same as: \$5{11/41}\$ km/h.

### Question 2

A train passes two persons walking in the same direction as the train. The time it takes to move past the man running at 5km/h is 8sec, whereas the time it takes to cross the other man running at 6km/h is 9sec. What is the speed of the train?

A

14km/h.

B

15km/h.

C

13km/h.

D

16km/h.

Soln.
Ans: a

Let the speed of the train be v km/h. Length of the train calculated with the data for the first man = \$(v - 5) × 8\$. It should equal the length obtained from the data for the second man. So \$(v - 5) × 8\$ = \$(v - 6) × 9\$. Please note that we have not converted seconds to hours because that factor will ultimately cancel away. Solving for v we get 14km/h.

### Question 3

Two cars A and B begin to move towards each other and meet midway after travelling equal distance. What is the initial distance between them if the speeds of A and B are 2 km/h and 4 km/h, and B started 1 hour late?

A

8 km.

B

9 km.

C

7 km.

D

\$3{2/3}\$ km.

Soln.
Ans: a

If the distance between them is L, they meet after travelling L/2. Equating the times they travelled, \$L/{2 × 2} = L/{2 × 4} + 1\$. Solving for L we get L = 8 km.

### Question 4

An object covers a distance of 2800 meters in 21 minutes. What is its speed?

A

8 kmph.

B

9 kmph.

C

7 kmph.

D

10 kmph.

Soln.
Ans: a

The speed = distance/time. It is \$2800/{21 × 60}\$ × \$18/5\$ = 8 kmph.

### Question 5

Two cars, A and B, start to move towards each other. If they meet when A has travelled \$(1/6)\$th of the distance, what is the ratio of the speed of B to the speed of A?

A

5.

B

6.

C

4.

D

7.

Soln.
Ans: a

Let the speeds of the cars be u and v and the initial distance between them be L. When they meet they have travelled for the same time. So \$(L/6)/u = ({5L}/6)/v\$. The ratio \$v/u\$ = 5.

Updated on 2020-02-07. Published on: 2016-05-06

Posted by Parveen(Hoven),
Aptitude Trainer