Each week Carina puts 20 more seashells in a jar than she did the week before. If there are 50 seashells in the jar this week, how many will there be in a month?
Use reasoning to answer the following question.
130
In one week there will be 50 + 20 = 70 seashells.

In two weeks there will be 70 + 20 = 90 seashells.

In three weeks there will be 90 + 20 = 110 seashells.

In four weeks there will be 110 + 20 = 130 seashells.

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Final answer: 130