Question

Monica and Brianna are training for a bike race; their goal is to bike 34 miles. On Saturday Monica only biked 10% of that distance. She told Brianna, “I know that I can find 10% of 34 miles by dividing 34 by 10.” Brianna said, “That makes it easy to figure out how far I biked! Since I biked 20% of that 34 miles on Saturday, I can just divide 34 by 20 to find how far I biked.” Will Brianna’s strategy give her the correct distance she biked on Saturday? Explain why or why not.

Answer 1

No, because dividing by 20 is the same as multiplying by 0.05, which would mean that this would give her 5% not 20%. Therefore to correctly find 20% she needs to multiply by 0.2 which is the same as dividing by 5.