Question

Juan is saving to purchase a new computer and has saved $213. He earns $3 a day and needs at least $654 for the computer he would like to purchase. How many weeks will it take him to save for the computer?

Answer 1

Juan has to work at least 21 weeks.

Explanation:

Juan earns $3 a day, then he earns $21 per week.

Let x be the number of weeks Juan works. He will earn $21x in x weeks.

Juan has saved $213,

He earns $21x,

Juan's total earnings are $213+$21x.

He needs to save at least $654, so

`213+21x\ge 654\\ \\21x\ge 654-213\\ \\21x\ge 441\\ \\x\ge 21`

Juan has to work at least 21 weeks.