There were 15 moles of a substance present initially in a system, 25 moles were added to it and a reaction occurred so that its moles are reduced by 50%, what are the final moles of a substance in the system?
(a) 10
(b) 15
(c) 20
(d) 40
The question was asked in an interview for job.
This interesting question is from Material Balance Concept in division Introduction to Material Balances of Basic Chemical Engineering