Mary has 5 2/5 yards of string. Written as an improper fraction, 5 2/5 = 27/5 yards of string.
The friend was given 2/3 of the string. The friend received 2/3 * 27/5 = 18/5 yards which is the same as 3 3/5 yards and also 3.6 yards.
After Mary gave the friend the string, Mary had 27/5 - 18/5 = 9/5 yards left.
9/5 yards is the same as 1 4/5 yard and also 1.8 yards.
