Question

Jonathan can jog 3 2/5 miles in 7/8 hour.Find his average speed in miles per hour

Answer 1

`\bf 3(2)/(5)\implies \cfrac{3\cdot 5+2}{5}\implies \cfrac{17}{5}\\\\ -------------------------------\\\\ \cfrac{3(2)/(5)~mi}{(7)/(8)~hr}\implies \cfrac{(17)/(5)~mi}{(7)/(8)~hr}\implies \cfrac{17}{5}mi\cdot \cfrac{8}{7}hr\implies \cfrac{17\cdot 8~mi}{5\cdot 7~hr}\implies \cfrac{136~mi}{35~hr} \\\\\\ \textit{which is rougly }\approx 3.886(mi)/(hr)`