3. $18 off or 15%
we want to know when these are the same so
when the price is 120 18 off will give you a price of 102. 15% off will give you a price of 102 as well.
4. 48 computers 30% increase
you just need to find 30% of 48 and add it to 48
48×.3=14.4
14.4+48=62.4 so they need to sell 63 computers. if they only sell 62 it is less than 30% and they cant sell 2/5 a computer!
5. buys at 12 sells at 30
discounted 25% buys 2 with 4% tax
discounted price is 30-30×.25=22.5
so 2 shirts is 22.5+22.5=45 multiply by .04 to get tax 1.80 add this to find the total 46.80
discounts by 55% so find 55% of 30 and subtract from 30 this is 13.5 since she buys them for 12 she will make 1.50 on each shirt.