A car travels a distance of 560 km in 9.5 hours partly at a speed of 40 km `h^(-1)` and partly at 160 `km h^(-1)` . What is the distance it travel at the speed of 160 km `h^(-1)` ?

Options

A. 120 km
B. 240 km
C. 320 km
D. 360 km

Answer

B

Explanation

Let the distance it travelled at the speed of 160 `kmh^(-1)`
be x km
`therefore (x)/(160) + ((560 -x))/(40) = 9.5`
`(x + 4 (560 -x))/(160) = 9.5`
`x + 2240 - 4x = 1520`
`3x = 720`
x = 240 km