The usual price of a pencil sold at Shop K and L is $28. During a sale, a discount of 25% is given to every pencil sold at Shop K. At Shop L, a discount of 50% is given to the 6th pencil for every 6 pencils sold. How much cheaper would it be if Diana buys 16 pencils from Shop K instead of Shop L?

	Shop K	Shop L
Price of 1 pencil	75%  $21	100% $28
Every 6th pencil		50% $14

Price of 1 pencil from Shop K in percentage
= 100% - 25%
= 75%

Price of 1 pencil from Shop K at 25% discount
= 75% x 28
= ⁷⁵₁₀₀ x 28 
= $21

Cost of 16 pencils from Shop K
= 16 x 21
= $336

Price of the 6th pencil from Shop L in percentage
= 100% - 50%
= 50%

Cost of 6th pencil at Shop L
= 50% x 28
= ⁵⁰₁₀₀ x 28 
= $14

Cost of 1 set of 6 pencils at Shop L
= 28 x 5 + 14
= $154

Number of sets of 6 for pencils at Shop L
= 16 ÷ 6
= 2 r 4

Cost of 2 sets of 6 pencils at Shop L
= 2 x 154
= $308

Cost of 4 pencils at Shop L
= 4 x 14
= $56

Cost of 16 pencils at Shop L
= 308 + 56
= $364

Amount cheaper if Diana buys 16 pencils from Shop K instead of Shop L
= 364 - 336
= $28

Answer(s): $28