Question

.A car takes 7 hours to cover a certain distance at the speed of 48 km/h. If the speed is decreased by
20 km/h, how much time will it take to cover the same distance?​

Answer 1

Given data:-

• A car takes 7 hours to cover a certain distance at the speed of 48 km/hr.
• The speed is decreased by 20 km/hr.

Here

• Speed of car = 48 km/hr
• Time = 7 hour

Solution:-

{According to given}

Now, we use fromula of speed:-

—› Speed of car = {Distance}/{Time}

—› 48 = {Distance}/7 i.e.

—› Distance = 48 × 7

—› Distance = 336 km ..... ( 1 )

Speed is decreased by 20 km/hr from 48 km/hr. hence,

—› Speed of car = {48 - 20}km/hr

—› Speed of car = 28 km/hr ....( 2 )

Now, we use fromula of speed:-

—› Speed of car = {Distance}/{Time}

{from eq. ( 1 ) & eq. ( 2 )}

—› 28 = 336/{Time} i.e.

—› Time = 336/28

—› Time = 12 hour

Hence, car take 12 hour to cover 336 km with speed 28 km/hr.