Answer:
1.9 feet = 19/10 feet = 1-9-10 feet
(I provided the answer as a regular number, as a mixed number, and as an improper fraction. Feel free to use whichever feels best to you).
Explanation:
We can find the remaining amount of string by subtracting the amount of string used from the total amount of string.
Since Jason used 2 2/5 feet of string and started with 4 3/10 feet of string, we subtract 2 2/5 from 4 3/10.
Step 1: We can subtract improper fractions by subtracting the whole numbers and the fractions themselves. Then, we can combine the result at the end:
(4 - 2) + (3/10 - 2/5)
2 - (5/50)
2 - 1/10
1.9
Step 2: When we convert 1.9 into a mixed number, we get 1 9/10 (in the form you used, it's 1-9-10).
As a mixed number, it's 19/10