Samuel had 2 strings.
The first string was
3
5
m long.
The second string was
1
4
m shorter than the first string.
(a) What was the length of the second string in fractions?
(b) What was the total length of both strings in fractions?
I see you haven't yet learned to interpret users' nonstandard formatting, even though he specifically mentioned fractions. The question should read:
Samuel had 2 strings.
The first string was 3/5 m long.
The second string was 1/4 m shorter than the first string.
Now finish it off.
(a) The second string was 3/5 m - 1/4 m = 12/20 m - 5/20 m = 7/20 m long.
(b) The total length of both strings was 3/5 m + 7/20 m = 12/20 m + 7/20 m = 19/20 m.
(a) The second string was 3 m long (5 m - 1 m = 4 m).
(b) The total length of both strings was 3 m + 4 m = 7 m.