a$.$ Pn Nasibah plans to retire and buy a house in Alor Star, Kedah. She has found a house Which she intends to buy, the price of the house currently is RM$150000.$ The house value is expected to increase at a rate of $5\%$ annually.

Pn Nasibah plans to save her money and buy the house. Assuming she can earn $10\%$ annually on her investments, how much must she invest at the end of each year for the next $20$ years to be able to buy her dream house when she retires.

b$.$ Ashira place RM$25000$ in a saving account paying an annual compound interest of $8\%$ for $3$ years. After $3$ years she then moves it into a saving account that pays $10\%$ interest compounded annually. How much will her money grow at the end of $6$ years.

c$.$ Kak Ton is saving for her child education. She plan to deposit RM $500$ beginning of the year for the next $5$ years in a bank that is giving $6\%$ interest. Calculate the amount will Kak Ton accumulate at the end of $5$ years.