Arithmetic aptitude :: Time and Distance :: General Questions

• Time and Distance - General Questions
• Time and Distance - Data Sufficiency 1
• Time and Distance - Important Formulas and Facts

1. Speed $=\left(\frac{Distance}{Time}\right)$, Time $=\left(\frac{Distance}{Speed}\right)$, Distiance $=(Speed\times Time)$

2. $x$ km/hr $=\left(x\times\frac{5}{18}\right)$ m/sec

3. $x$ m/sec $=\left(x\times\frac{18}{5}\right)$

4. If speed ratios of X and Y is $x:y$, then the time ratio by them to cover same distance $=\frac{1}{x}:\frac{1}{y}$ or $y:x$

5. Suppose an object covers a certain distance at $x$ km/hr and an equal distance at $y$ km/hr. Then, the average speed of during the

whole travel is $\left(\frac{2xy}{x+y}\right)$ km/hr.

A dog takes 4 leaps for every 5 leaps of a hare but 3 leaps of a dog are equal to 4 leaps of the hare. Compare their speeds.

Answer:

Explanation:

Let the distance covered in 1 leap of the dog be $x$ and that covered in 1 leap of the hare be $y$.

Then, $3x=4y$ $\Rightarrow x=\frac{4}{3}y$ $\Rightarrow 4x=\frac{16}{3}y$

Ratio of speeds of dog-and-hare = Ratio of distances covered by them in the same time

$=4x:5y$ $=\frac{16}{3}y:5y$ $=\frac{16}{3}:5$ = 16:15

A cyclist covers a distance of 750 m in 2 min 30 sec. What is the speed in km/hr of the cyclist ?

Answer:

Explanation:

speed $=\left(\frac{750}{150}\right)$ m/sec

$=\left(5\times\frac{18}{5}\right)$ km/hr = 18km/hr

How many minutes does Aditya take to cover a distance of 400 m, if he runs at a speed of 20 km/hr ?

Answer:

Explanation:

Aditya's speed = 20 km/hr $=\left(20\times\frac{5}{18}\right)$ m/sec $=\frac{50}{9}$ m/sec

Time taken to cover 400m $=\left(400\times\frac{9}{50}\right)$ sec = 72 sec $=1\frac{12}{60}$ min $=1\frac{1}{5}$ min

• Time and Distance - General Questions
• Time and Distance - Data Sufficiency 1