Question

14 from 2018 to 2021, singapore’s gross national income (gni) increased by 9.24%. from 2018 to 2019, the gni increased by 3.63%. from 2019 to 2020, the gni decreased by 5.56%. calculate the percentage increase in the gni from 2020 to 2021.

Explanation:

Step1: Let the GNI in 2018 be \( G \).

First, find the GNI in 2019. Since it increased by 3.63% from 2018 to 2019, the GNI in 2019 is \( G(1 + 0.0363)=1.0363G \).

Step2: Find the GNI in 2020.

It decreased by 5.56% from 2019 to 2020, so the GNI in 2020 is \( 1.0363G(1 - 0.0556)=1.0363G\times0.9444 \approx 0.9786G \).

Step3: Let the percentage increase from 2020 to 2021 be \( x \).

The total increase from 2018 to 2021 is 9.24%, so the GNI in 2021 is \( G(1 + 0.0924)=1.0924G \).
We also know that the GNI in 2021 can be expressed as the GNI in 2020 times \( (1 + x) \), so:
\( 0.9786G(1 + x)=1.0924G \)
Divide both sides by \( G \) (since \( G
eq0 \)):
\( 0.9786(1 + x)=1.0924 \)
Then, \( 1 + x=\frac{1.0924}{0.9786}\approx1.1163 \)
So, \( x\approx1.1163 - 1 = 0.1163 \), which is 11.63%.

Answer:

The percentage increase in GNI from 2020 to 2021 is approximately 11.63%.