Answer:
Keith spent 37 and a half minutes dusting.
Explanation:
Given that Keith spent 2 1/2 of hours doing chores, and I have spent 1/4 of that time dusting, to determine how much time did Keith spend dusting, the following calculation must be performed:
1/2 = 0.5
1/4 = 0.25
2.5 x 0.25 = X
0.625 = X
1 = 60
0.625 = X
0.625 x 60 = X
37.5 = X
Therefore, Keith spent 37 and a half minutes dusting.