Write 48 as a product of its prime factors

Break it down 

48 = 2x24 = 2^2 x12 = 2^3 x 6 = 2^4 x 3 

This is what you were looking for: 48 as a product of prime factors! 
48 = 2x2x2x2x3 = 2^4 x 3 

On monday,mrs.wise bought 3 lbs of apples at $4per lb= 4*3=$12on tuesday ,20%off and she buy 5 lbs of apples = $4-20%=3.20*5lb=$16example: other wise when she buy 5lbs on monday she have to spend 4*5=20