Question

Tina took 2 and 1/3 hours to travel 4/9 of the distance between Town A to Town B at an average speed of 72 km/ hr . What was Tina's average speed if she took 4 hours 12 min to travel from Town A to Town B .​

Answer 1

Answer

Let the total distance be D

$\sf \: time \: took \: 2 \frac{1}{3} = \frac{7}{3} hour \: to \: travel \: \\ \sf \: \frac{4}{9} of \: the \: distance \: d \: i.e \: she \: travelled \: \\ \sf \: we \: know \: that \: distance \: = speed \times time \\ \sf \: \frac{4d}{9} = \frac{7}{3} \times 72 \\ \sf \: \frac{4d}{9} = 168 \\ \sf \: d = \frac{168 \times 9}{4} = 378km$

$\sf \: now \: average \: speed \: to \: complete \: this \: \\ \sf \: distance \: in \: 4hr \: 12min \\ \sf( 4\frac{12}{60} = \frac{12}{5} hr) \: is \: = \frac{378}{ \frac{21}{5} } \\ \sf \: \frac{378 \times 5}{21} = 90km /h$

Answer 2

Answer:

Absolutely the ans is 90km