I need 40% overall to pass my exam. So far I have got:

55% of an exam worth 45% of overall grade, and

75% of an essay worth 10% of overall grade

I have one more exam, worth 45% of the overall grade. What is the minimum percentage score I need to achieve to get an overall grade of 40%?

I have no idea how to do the math, so any help is great.

Thanks