Carnot engine physics question please help!!

Question

A heat engine does 300 J of work per cycle while exhausting 550 J of heat to the cold reservoir. What is the engine's thermal efficiency in percentage? answer in two significant figures

A Carnot engine with a hot-reservoir temperature of 370 degree's C has the same thermal efficiency. What is the cold-reservoir temperature in C?

Answer 1

1st part:

e = W(engine) / Q(hot) = 300J / 550J = ...

2nd part:

e = 1 - T(c)/T(h)  --> T(c) = T(h) * [1 - e] = ...