Question

4. In one semester, Doug and Laura spent a combined 230 hours in the tutoring lab. If Doug

spent 10 hours less than twice the hours Laura did, how many hours did Doug spend in
the lab?

Answer 1

80 hours

Explanation:

let d represent doug, let l represent laura

first, set up a system of equations representing the problem:

since doug spent 10 less than twice the hours laura did, and we know that the total amount of hours they spent together is 230:

l=2d+10

d+l=230

then solve:

*first i rearranged the equations so i can solve this system of equations using elimination method*

l-2d=10

l+d=230

*subtract*

3d=240

d=80

so, doug spent 80 hours in the lab