Dhillon invested $1,000. Their investment grew to earned $1,600 earning an interest rate of 2.5% simple. How many years was the money invested?

Manraj and Dhillon have received offers for 18 month contracts. Manraj has been offered $20000 cash. Dhillon has been offered $6000 in 3 months $7000 in 9 months and $8000 in 15 months. Find the present value of Dhillon's payment option if interest is 12% simple. (use today as the focal date) Who has the better contract? Briefly explain.