A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)

Answer 1

eff = [(126-77)/126]*100 = ?

Answer 2

I got 38.88 is that correct?

Answer 3

I obtained 38.8889 so I would round that to 38.9 but I believe you're allowed only 2 s.f.

Answer 4

so basically 39%?