Question

The speeds of three cars are in the ratio 5: 3: 4. The ratio between the time taken by these cars to cover the same distance is :

• A. 12 : 20 : 15
• B. 10 : 13 : 15
• C. 16 : 13 : 15
• D. 12 : 13 : 15

Answer 1

Answer:

A. 12 : 20 : 15

For the same distance, time is inversely proportional to speed.

Speeds ratio = 5 : 3 : 4

So time ratio = inverse of speeds:
$\frac{1}{5} : \frac{1}{3} : \frac{1}{4}$

Take LCM of 5, 3, 4 = 60

$= \frac{60}{5} : \frac{60}{3} : \frac{60}{4}$
= 12 : 20 : 15

Final Answer: 12 : 20 : 15