Question

A car covers 30 km at a uniform speed of 30km/hr. What should be its speed for the next 90km if the average speed for the entire journey is 60 km/hr?

Answer 1

60=30(1hour)+90(x Hours)➗ 1+x. by finding x we get time. Then we can find average speed.

Answer 2

${ \textbf{ \blue{\underline{ \red{\underline{ \red{Question : - } }}}}}}$

A car covers 30 km at a uniform speed of 30km/hr. What should be its speed for the next 90km if the average speed for the entire journey is 60 km/hr ?

${ \textbf{ \blue{\underline{ \red{\underline{ \red{Solution : - } }}}}}}$

{According to question}

A car covers 30 km at a uniform speed of 30km/hr.

Hence we know that, a car covers 30 km in 1 hour .

To find speed of car the next 90 km

Let, x be the speed of car for 90 km

{According to question}

Average speed for the entire journey is 60 km/hr.

${ \bf{ \dashrightarrow{Average \: speed = \frac{ Total \: distance }{Total \: time} }}}$

${ \bf{ \dashrightarrow{60 = \frac{ 30 + 90 }{1 + x} }}}$

${ \bf{ \dashrightarrow{1 + x= \frac{ 30 + 90 }{60} }}}$

${ \bf{ \dashrightarrow{1 + x= \frac{ 120 }{60} }}}$

${ \bf{ \dashrightarrow{1 + x= 2}}}$

${ \bf{ \dashrightarrow{x = 2 - 1}}}$

${ \bf{ \dashrightarrow{x = 1 \: hour}}}$

Hence average speed of car for 90 km is 90 km/hr.