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