Answer! A car travels from A to B at a speed of 30 mph then returns, using the same road, from B to A at a speed of 65 mph. What is the average speed for the round trip?

Step-by-step explanation:

s₁ = s₂ = x       {the distance from A to B}

s = s₁ + s₂ = x + x = 2x      {the distance of the round trip}

t = t₁ + t₂               {the time of the round trip}

v₁ = 30 mph      

v₂ = 65 mph

t₁ = s₁/v₁ = x/30 h       {the time of trip from A to B}

t₂ = s₂/v₂ = x/65 h      {the time of trip from B to A}

The average speed:

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have

step-by-step explanation: