Marcie can cut the grass in 3 hrs. working alone. When her younger brother Rod helps, it takes 2 hrs.

How long would it take Rod to cut grass alone?

grass/marcie alone = 3 hrs

grass/marcie and rod = 2 hrs

Marcie can cut the grass in 3 hrs. working alone. When her younger brother Rod helps, it takes 2 hrs.

How long would it take Rod to cut grass alone?

grass/marcie alone = 3 hrs

grass/marcie and rod = 2 hrs

How long would it take Rod to cut grass alone?

grass/marcie alone = 3 hrs

grass/marcie and rod = 2 hrs

- stapel_eliz
**Posts:**1628**Joined:**Mon Dec 08, 2008 4:22 pm-
**Contact:**

To learn how to set up and solve this sort of exercise, tryMarcie can cut the grass in 3 hrs. working alone. When her younger brother Rod helps, it takes 2 hrs.

How long would it take Rod to cut grass alone?

Once you understand the basic terms and techniques, do the standard set-up:

. . .time to complete task:

. . . . .Marcie: 3

. . . . .Rod: r

. . . . .together: 2

. . .portion completed per time unit:

. . . . .Marcie: 1/3

. . . . .Rod:

. . . . .together:

Complete the table, add the input amounts per unit time, set equal to the output amount, and solve for the variable.