Question

a man covers q distance of 24km in 3 and 1/2 hours partly on foot at the speed of 4.5km/h and only on bicycle at the speed of 10k/h .find the distance covered on foot

Answer 1

$distence \: on \: foot \: be \: x \\ t1 = \frac{x}{4.5} \\ t2 = \frac{24 - x}{10} \\ t1 + t2 = 3.5 \\ \frac{x}{4.5} + \frac{24 - x}{10} = 3.5 \\ \frac{10x}{45} + \frac{24 - x}{10} = \frac{35}{10} \\ \frac{20x + 216 -9x}{90} = \frac{35}{10} \\11x + 216 = 35 \times 9 \\ 11x =315 - 216 \\ x = \frac{99}{11} = 9km$