Question Statement :

Amar is 20% less efficient than Sachin. Amar, when working alone, takes 30 days to finish the job. He works alone for ‘n’ days. After that, Sachin joins him and the two work together to finish the job in exactly 20 days (counting from the day Amar began working alone). What is the value of ‘n’?

Type in your answer as an integer. For example, if your answer is 17, type 17