Answer to Question #159017 in Algebra for Ali

Question

The time, T, taken for a journey of a fixed distance is inversely proportional to the average speed S.

When S = S1, T = T1

On another journey, the speed S1 is increased by 40%

Work out the time taken for this journey.

Give your answer as a fraction of T1

Answer 1

The time, T, taken for a journey of a fixed distance is inversely proportional to the average speed S.

$$T_1=\dfrac{C}{S_1}$$

On another journey, the speed S1 is increased by 40%

$$S_2=1.4S_1$$

Then

$$T_2=\dfrac{C}{S_2}=\dfrac{C}{1.4S_1}=\dfrac{T_1}{1.4}$$

$$T_2=\dfrac{T_1}{1.4}$$