The selling price would be $11.20.
40% = 40/100 = 0.4
The mark up is 40% of the cost; this means 40% of 8:
40% of 8 = 0.4(8) = 3.20
8 + 3.20 = 11.20
5) 5! = 5*4*3*2*1
6) use the 6 choose 2 combination formula: C(6,2) = 6!/(2!)(6-2)!
= 6!/(2!)(4!)<span />
