Question

Each year 80,000 people move into a city, 70,000 people move out, 18,000 are born, and 11,000 die. Write a balance on the population of the city.

(a) 17,000 P/yr

(b) 15,000 P/yr

(c) 20,000 P/yr

(d) 22,000 P/yr

I got this question in semester exam.

I need to ask this question from Material Balance Numericals in division Material Balance of Bioprocess Engineering

Answer 1

The correct answer is (a) 17,000 P/yr

Explanation: Let P denotes people,

Input + Generation – Output – Consumption = accumulation

80,000 P/yr + 18,000 P/yr – 70,000 P/yr – 11,000 P/yr = A(P/yr)

A = 17,000 P/yr

Each year the city’s population increases by 17,000 P/yr.