Question

A and B left kanpur simultaneously and travelled Lucknow.A speed was 20km/h and B speed was 12km/h.3 hours later C left kanpur and travelled in the same direction.after some time he overtook B and 120 minutes further he overtook A.find speed of C

Answer 1

Answer:

37.62

Step-by-step explanation:

let say after x hrs C overtook B

and speed of C = C km/hr

distance covered by C = Cx km

distance covered by b =12×(3+x)

= 36+12x

Cx = 36 + 12x

after 120 mins , 2hrs more C overtook A

distance covered by C

=C (x+2) km

distance covered by A =20(x + 5) km

CX + 2C = 20x + 100

2C = 8x + 64

C = 4x + 32

(4x+32)x = 36 + 12x

(x +8)x = 9 + 3x

x^2 +5x - 9=0

x =1.405

C =37.62 km

speed of C =37.62 km/hr