Adelle used 10 centimeters of tape to wrap 2 presents. How much tape will Adelle need in all if she has to wrap 3 presents? Assume the relationship is directly proportional.

Answer 1

Hi Romanie. In order to answer this question, we have to set up equivalent ratios. While we are doing so, we should:

let x represent the length of tape Adelle will need to wrap 3 presents

Our equivalent ratios will be:

10 centimeters of tape/ 2 presents = x centimeters of tape/ 3 presents

We can now cross multiply (numerator 1 x denominator 2 = numerator 2 x denominator 1) and solve for x.

10 centimeters of tape/ 2 presents = x centimeters of tape/ 3 presents

30 centimeters of tape = 2x

divide by 2 on both sides to get the value of x.

x= 15 centimeters of tape

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