2020 Cayley Problem 18

Nate is driving to see his grandmother. If he drives at a constant speed of 40 km/h, he will arrive 1 hour late. If he drives at a constant speed of 60 km/h, he will arrive 1 hour early. At what constant speed should he drive to arrive just in time?

\textbf{(A)}\ 56 \text{ km/h}\quad \textbf{(B)}\ 80 \text{ km/h}\quad \textbf{(C)}\ 54 \text{ km/h}\quad \textbf{(D)}\ 48 \text{ km/h}\quad \textbf{(E)}\ 58 \text{ km/h}

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Cayley contests here.