Question

Christiana and Marlena opened their first savings accounts on the same day. Christiana opened her account with $55 and plans to deposit $10 every month. Marlena opened her account with $35 and plans to deposit $15 every month. After how many months will their two accounts have the same amount of money? What will that amount be?

Answer 1

Answer:

6.5 weeks.

55+50=105

35+60=95

It gets too wide when we double again.

55+ 100 =155

35+150=185

Therefore 55+70 =125

35+105= 125  Still too wide.

55+60=115

35+90= 125

The answer is between 6+ 7 weeks.

We then look at days.

Divide 55 weeks into 6.5 weeks less one day. Then apply 6.5

8.5 x 6.5 = 55  but when we plus 8.5+6.5=15  

Divide 35 weeks into 6.5 weeks no remainder

5.5 x 6.5 = 35.75 =12

We see the ratio is 4:5

Banks round down and up for .5 answers.

Therefore both decimals round up so the answer is 6.5 weeks.

Step-by-step explanation:

Answer 2

Answer: it will take 4 months for the amount to be the same and the amount would be $95

Step-by-step explanation:

Let x represent the number if months it will take for the two accounts have the same amount of money.

Christiana opened her account with $55 and plans to deposit $10 every month. This means that the amount that in the account after x months would be

10x + 55

Marlena opened her account with $35 and plans to deposit $15 every month. This means that the amount that in the account after x months would be

15x + 35

For the amount in the accounts to be the same, the number of months would be

15x + 35 = 10x + 55

15x - 10x = 55 - 35

5x = 20

x = 20/5

x = 4

The amount would be

15 × 4 + 35

= 60 + 35

= $95