Firstly, the rate of increase of Canton = 80/7720 = 0.010
The rate of increase of HP = 120/3200 = 0.0375
Apply the formula of compound interest==> A =A'(1+i)^n
The population will be equal when the following equality is satisfied
7720(1+0.01)^n = 3200(1+0.0375)^n
or
7720x1.01^n = 3200x1.0375^n
Divide both sides by 3200 ===>(193/80)x1.01^n=1.0375^n
Answer: 3/8x
To find the least common denominator first convert all integers and mixed numbers (mixed fractions) into fractions. Then find the lowest common multiple of the denominators. This number is same as the least common denominator .You can then write each term as an equivalent fraction with the same LCD denominator.