What is the probability of clearing the exam if he practises every concept twice at home?

Directions: Read the following information and answer the given question.

Even though Shreyan works hard, he does not score good marks in Mathematics. He can't understand the concepts properly. In a parent teacher meeting, his teacher tells his parents that his chances of passing the exam are 30%. But, he can increase his chances of clearing the exam by 10% if he practices every concept at home twice.