Kyle plans to save d dollars each month for 14 months. For 6 months, Kyle added an additional 20% of his $1,200 monthly earnings to his savings account. Which expression represents the amount Kyle has in his savings at the end of the 14 months?

An expression represents the amount Kyle has in his savings at the end of the 14 months is 14d+1440

Step-by-step explanation:

Kayla saves amount per month = d

Kayla saves amount in 14 months = 14d

For 6 months, Kyle added an additional 20% of his $1,200 monthly earnings to his savings account

Additional amount per month= 20% of 1200 =

Additional amount 6 months=

Amount in account after 14 months = 14d+1440

Hence An expression represents the amount Kyle has in his savings at the end of the 14 months is 14d+1440

4.5 minutes

Step-by-step explanation:

1 problem in 3 minutes is equivalent to a rate of 1/3 problem per minute, when their work together.

Let's call m to Marco's rate of work. Then Cliff's rate of work is m/2. The addition of Marco's and Cliff's rate of work make their combined rate of work, that is:

m + m/2 = 1/3

3/2*m = 1/3

m = 1/3 * 2/3 = 2/9    (2 problems in 9 minutes)

Then, it takes to marco 9/2 = 4.5 minutes to solve a problem