Chapter 1, Equations and Inequalities - 1.5 Use Problem Solving Strategies and Models - 1.5 Exercises - Problem Solving - Page 39: 32d

See below.

Using the previous parts, the distance covered by running is: $1.25\cdot12=15km$ Using the previous parts, the distance covered by cycling is: $\frac{4}{3}\cdot30=40km$ $40+15=55km$ Thus we verified what we had to.