22 divided by 486 the internet will not tell me and I found this so?

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

Find the value of x that will make l ll m

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.