An electrician buys a 3 meter lead. He uses 2/5 of the lead. what length of lead is left?

Using 2/5 will mean there is 3/5 left.
Mutiply the total length by the fraction left:
3 x 3/5 = (3 x 3) /5 = 9/5 - 1 and 4/5 meters left
Answer: 1 and 4/5 meters