Question

what is correct way to use slash (/)......?

Answer 1

You use the forward slash when indicating "or" "per" such as these example
Madame/Sir (Madame or Sir)
100km/hr (100 km per house)
you also use it when you see fractions or on website addresses. don't know if i helped..

Answer 2

thanks @lianacarolina

Answer 3

when you you state something but in the sentience it really could be both. (it depends on how they read it).like a/an