Let's assume that total no. of students in the school is x
Also , we are given that their are 140 students in 6th grade {Given} and no. of students in 6th grade is 40% of total no. of students in school i.e 40% of x {From Pie Chart} . Mathematically can be written as ;
![{\quad \qquad \sf \blacktriangleright \blacktriangleright \blacktriangleright 40 \% \: of \: x = 140}](https://img.qammunity.org/2023/formulas/mathematics/college/y0s1kxnsrth8xcr5fa94v4fbj7ony4h2hu.png)
![{: \implies \quad \sf x=(140* 100)/(40)}](https://img.qammunity.org/2023/formulas/mathematics/college/rwuowgfvd4d62mg5y6j46jnuezhulxdr3d.png)
After cancelling ;
So , Total population of school is 350
Hence, Option D) 350 is correct