[tex]{\pmb{\bf Assumption \: :-}}[/tex] 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 ;
[tex]{\quad \qquad \sf \blacktriangleright \blacktriangleright \blacktriangleright 40 \% \: of \: x = 140}[/tex]
[tex]{: \implies \quad \sf \dfrac{40}{100}\times x =140}[/tex]
[tex]{: \implies \quad \sf x=\dfrac{140\times 100}{40}}[/tex]
After cancelling ;
[tex]{: \implies \quad \sf x=350}[/tex]
So , Total population of school is 350
Hence, Option D) 350 is correct
