How can I create a word problem with the following expressions

15+2d

200-4m

For the first expression

15 + 2d

A possible word problem would be this:

A person saves $2 per day of money. Before he started saving, he had $15 dollars set aside. Look for the expression that expresses the total amount of money saved in terms of the number of days passed

The second expression is

200 - 2m

A possible word problem would be this:

The distance from school to the park is 200m. A kid riding a bike is traveling at a speed of 2m/s from the school to the park. Write an expression for the distance remaining between the park and the kid.