Answer :
5%
(Markup percent/100) × Cost price = Selling price - cost price
=> (Markup percent/100) × $14 = $21 - $14
=> (Markup percent/100) × $14 = $7
=> (Markup percent/100) = $7 / $14
=>
5%
(Markup percent/100) × Cost price = Selling price - cost price
=> (Markup percent/100) × $14 = $21 - $14
=> (Markup percent/100) × $14 = $7
=> (Markup percent/100) = $7 / $14
=>