Question

4. A Llane beft 30 minutes lats than its scheduled
time and in order to reach the destinate 1500km
away
in time, it had to increase its speed by
100kilometer per hour from the usual speed find its usual speed​

Answer 1

Answer:

S = d/t

$s = \frac{1500}{t + \frac{1}{2} }$

And

$s + 100 = \frac{1500}{t}$

Subtract the equation

$100 = 1500( \frac{1}{t} - \frac{1}{t + 0.5} )$

$\frac{1}{15} = ( \frac{1}{t} - \frac{1}{t + 0.5} ) \\ \frac{1}{15} = ( \frac{0.5}{ {t}^{2} + 0.5t } )$

${t}^{2} + 0.5t = 7.5$

Solving for t -

$t = 2.5 \: hour$

the usual speed

$s = \frac{1500}{3} = 500 \: \frac{km}{h}$