An electric firm finds that 4% of its resistors are defective. how many resistors do they have to make to deliver 5000 resistors?

Answer is 5000 resistors, the quesiton never said that they had to deliver working resistors

but if you wanted 5000 working resistors
the rest is working
100%=all
all-defective=working
100-4=96
96%=working
working=5000
find 100%
96%ofall=5000
percent means parts out of 100
96/100ofall=5000
times both sides by 100
96ofall=500000
divide both sides by 96
all=5028.33333
round up
5029 resistors must be made to deliver at least 5000 working ones