Answer:
a. Mason's rent will increase by $302.40 next year.
b. Mason's new rent per month next year will be $445.20.
Step-by-step explanation:
The first question is asking us how much Mason's rent will increase next year.
If the contract on Mason's apartment states that his rent will increase by 6% next year, and he is currently paying $420 per month, to calculate the increase of the rent next year, we will first have to multiply $420 by 12 months to calculate how much Mason is paying in rent a year:


Therefore, Mason is currently paying $5040 a year.
With this information, we will now need to calculate 6% of $5040. To calculate 6% of $5040, convert 6% to decimal form, and multiply it by $5040.
<em>6% means 6 per cent/hundred, so it can be represented as:</em>

<em>The fraction </em>
<em> can be represented as (we're two places behind the decimal, in the hundredths place)</em>:

Now, multiply the decimal form of 6% by $5040:


Therefore, Mason's rent will increase by $302.40 next year.
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To calculate Mason's new rent per month next year, we can divide $302.40 into 12 months to see the rent increase per month, and then add that quotient to Mason's current rent per month, $420:
÷ 

Now, that we know the rent per month will increase by $25.20 next year, we can add $25.20 to Mason's current rent per month:


Therefore, Mason's new rent per month next year will be $445.20.