# A cheetah was chasing and antelope which is 700m away. How many minutes will it take the cheetah, which is running at a constant speed of 110km/h to reach the antelope that is running at a constant speed of 75km/h?

Mar 17, 2016

1 min 12 sec

#### Explanation:

Cheetah has to reach the antelope with its relative speed $\left(115 - 75\right) = 35$ km/h.
Time = distance/speed = $\frac{0.7}{35}$ km/h=$\frac{1}{50}$h = 1.2 min = 1min 2sec..

Time $t = 0.02$ hours$= 1.2$ minutes

#### Explanation:

time (Cheetah)=time(Antelope)

${t}_{c} = {t}_{a}$

${d}_{c} / {v}_{c} = {d}_{a} / {v}_{a}$

$\frac{0.7 + x}{110} = \frac{x}{75}$

$75 \left(0.7 + x\right) = 110 x$

$75 \frac{0.7 + x}{5} = \frac{110 x}{5}$

$15 \left(0.7 + x\right) = 22 x$

$15 \left(0.7\right) + 15 x = 22 x$

$7 x = 15 \left(0.7\right)$

$x = 1.5 k m$

Solve time t:

$t = {d}_{a} / {v}_{a} = \frac{1.5}{75} = 0.02 \text{ }$hour

$t = 0.02 \cdot 60 = 1.2$ minutes

God bless....I hope the explanation is useful.