The usual price of a marker sold at Shop H and J is $10. During a sale, a discount of 20% is given to every marker sold at Shop H. At Shop J, a discount of 40% is given to the 7th marker for every 7 markers sold. How much cheaper would it be if Yen buys 16 markers from Shop H instead of Shop J?

	Shop H	Shop J
Price of 1 marker	80%  $8	100% $10
Every 7th marker		60% $6

Price of 1 marker from Shop H in percentage
= 100% - 20%
= 80%

Price of 1 marker from Shop H at 20% discount
= 80% x 10
= ⁸⁰₁₀₀ x 10 
= $8

Cost of 16 markers from Shop H
= 16 x 8
= $128

Price of the 7th marker from Shop J in percentage
= 100% - 40%
= 60%

Cost of 7th marker at Shop J
= 60% x 10
= ⁶⁰₁₀₀ x 10 
= $6

Cost of 1 set of 7 markers at Shop J
= 10 x 6 + 6
= $66

Number of sets of 7 for markers at Shop J
= 16 ÷ 7
= 2 r 2

Cost of 2 sets of 7 markers at Shop J
= 2 x 66
= $132

Cost of 2 markers at Shop J
= 2 x 6
= $12

Cost of 16 markers at Shop J
= 132 + 12
= $144

Amount cheaper if Yen buys 16 markers from Shop H instead of Shop J
= 144 - 128
= $16

Answer(s): $16