Question

Kai used a table to solve the previous challenge.He made an error.1. Describe something Kai did well.2. Describe what you would change.

Answer 1

Let x be the input to the machine

An increase of 20% means add 20% to the original amount of 100% or the new amount is 120%

The new amount is 36

x * 120% = 36

Changing the percent to a decimal is

x * 1.2 = 36

Divide each side by 1.2

x * 1.2/1.2 = 36/1.2

x = 30

Now to use the chart

He set up the chart correctly, but what is is multiplying by on the bottom line is incorrect.

WE are dividing by 1.2 or multiplying by 1/ 1.2 or .8333333 repeating.

The original number is 30 not 28.8