(A) The sum of first 15 terms of an A.P. is 750 and its first term is 15 . Find its $20^{\;\text{th }\;}$ term.OR(B) Rohan repays his total loan of ₹ 1,18,000 by paying every month starting with the first instalment of ₹ 1,000 . If he increases the instalment by ₹ 100 every month, what amount will be paid by him in the $30^{\;\text{th }\;}$ instalment? What amount of loan has he paid after $30^{\;\text{th }\;}$ instalment?