The city’s population has grown by 1/6 in 2020, and in 2021 it has grown by another 2/5 from 2020. If in 2019 the population was 155,880 people, what has it become in 2021?
Step 1: Determine the population growth in 2020.
We need to find what is 1/6of 155,880. This is the population growth in 2020. The key words “has grown by 1/6” point to multiplication.
155,880×(1/6) = (155,880/1)×(1/6)
= (155,880×1)/(1×6)
= (155,880)/(6)
= 155,880÷6
= 25,980
Step 2: Find the total population in 2020.
The total population in 2020 is the population in 2019 plus the population growth in 2020.
155,880 + 25,980 = 181,860
Step 3: Determine the population growth in 2021.
We need to find what is 2/5 of 181,860. Again, we find the key words “has grown by 2/5” to be sure that we should use multiplication.
181,860 × (2/5) = (181,860/1) × (2/5)
= (181,860×2)/(1×5)
= (363,720/5)
= 363,720 ÷5
= 72,744
Step 4: Find the total population in 2021.
The total population in 2021 is the population in 2020 plus the population growth in 2021.
181,860 + 72,744 = 254,604
The city’s population in 2021 is 254,604 people.
