Explanation:
he jogs 3 2/5 miles in 2/3 of an hour.
3 2/5 miles are 17/5 miles.
now, to get mph as speed unit, we need to bring the 2/3 hour to 1 hour.
we need to multiply 2/3 by a factor to get 1
2/3 × x = 1
2x = 3
x = 3/2
since we have to multiply the denominator of the ratio by 3/2, we also need to multiply the numerator by the same value to keep the overall value of the ratio/fraction the same.
17/5 / 2/3 × 3/2 / 3/2 = (17/5 × 3/2) / (2/3 × 3/2) =
= ((17×3)/(5×2)) / ((2×3)/(3×2)) =
= (51/10) / 1 = 51/10 = 5.1 mph
so, his jogging speed is 5.1 mph.