Question

Jordan is starting to save $150 to buy a new cell phone. In December, he saved $5. In January, he plans twice as much as he did in December, for a total savings of $15 ($5 + $10). If Jordan continues to save twice as much he saved from the previous month, in which month will his total savings will be enough to buy the phone.

Answer 1

Answer: The fifth month; By April Jordan would have saved more than enough to buy a new phone.

Explanation:

Dec $5

Jan $10

Feb $20

Mar $40

Apr $80

Dec + Jan = $15($5+$10)

Dec+ Jan + feb = $35($5+$10+$20=$35)

Dec+ Jan + feb + mar = $75 ($5+$10+$20+$40=$75)

Dec+ Jan + feb + mar + apr = $155

($5+$10+$20+$40+$80=$155)

Answer 2

Answer: At the Month May Jordan as able to get enough money to buy the phone.

Work:

December:$5

January:$10

February:$20

March:$40

April:$80

May:$160 <--Answer

____________________________________________________________In the problem Jordan saves $5 at December, then at January Jordan saved $10 which is twice as December's saved money amount. February, Jordan saved $20, which is twice as January's saved money amount. March is $40, which is twice as February's saved money amount. For April it is $80, which is twice as March's money amount, May is $160 which is twice as April's money amount. Or another way to say this is by starting at $5. Then, keep multiplying by 2 for each month until you get $150 or more. When you do, stop at the month that gets you $150 or more. When i did this exact method, I got $160 on the Month of May. $160 is more than enough for Jordan to buy his phone. So the month May is the correct answer where Jordan can get enough money for his phone.