Question

the retail price of an alarm clock is $39.99, and its cost to the retailer is $20.(A) what is the markup percentage based on its cost?(B) based on its retail price?

Answer 1

$20 to basically $40 would be a 100% percentage increase since the cost doubles, if it were to jump up to $30 than it would be a 50% percent increase, but since its double its 100%.