Yash scored 40 marks in a test getting 3 marks for each right answer a

This question was asked in Ex 3.5, 4

Yash scored 40 marks in a test getting 3 marks for each right answer and losing 1mark for each wrong answer. Had marks been awarded for each correct answer and 2marks been deducted for each incorrect answer then. Yash would have scored 50marks.how many questions were there in the test