Dear Student
Length of cloth = 25 m
Length of cloth cut for one curtain = 3 m 50 cm = 3.50 m
Total cloth used to making five curtains = 5 x 3.50 m = 17.50 m
Therefore, length of cloth left = Length of cloth - length of cloth used for five curtains
= 25 - 17.50
= 7.5 m
Regards