Question

A car travels a distance of 840 km at a uniform speed. If the speed of the car
is 10 km/hr more, it takes 2 hours less to cover the same distance. The
original speed of the car was
(a) 45 km/hr (6) 50 km/hr
(c) 60 km/hr (d) 75 km/hr
detineti
Du​

Answer 1

$\huge\bf\pink{ANSWER}$

CORRECT OPTION:C

Let the original speed be x km/hr.

Let the original speed be x km/hr.Then, [ 840/x - 840/( x + 10) ] = 2

Let the original speed be x km/hr.Then, [ 840/x - 840/( x + 10) ] = 2⇒ 840 (x + 10) - 840x = 2x (x+10)

Let the original speed be x km/hr.Then, [ 840/x - 840/( x + 10) ] = 2⇒ 840 (x + 10) - 840x = 2x (x+10)⇒ x2 + 10x - 4200 = 0

Let the original speed be x km/hr.Then, [ 840/x - 840/( x + 10) ] = 2⇒ 840 (x + 10) - 840x = 2x (x+10)⇒ x2 + 10x - 4200 = 0⇒ (x + 70) (x - 60 ) = 0

Let the original speed be x km/hr.Then, [ 840/x - 840/( x + 10) ] = 2⇒ 840 (x + 10) - 840x = 2x (x+10)⇒ x2 + 10x - 4200 = 0⇒ (x + 70) (x - 60 ) = 0∴ x = 60 km/hr.

Answer 2

Answer:

your answer is (c). 60 km per hour