A clothing store reduces the price of an item by 20% if it is not sold after 3 weeks. It reduces the price a further 30% if the item is still unsold after 6 weeks.
And, after 7 weeks if the item is unsold, a further 10% reduction is made.

a) Estimate the price, after 8 weeks, of a coat that had a regular price of $289.50.
b) Calculate the sale price, including the sales tax.