ANSWER
[tex]200[/tex]
EXPLANATION
From the given data;
The ratio of the grandmother who buys lunch : all grandmother is;
[tex]\begin{gathered} 35:50 \\ =7:10 \end{gathered}[/tex]
To calculate the corresponding values of grandmothers who buys lunch and all grandmother;
For the 3rd column;
When all grandmother is 150.
The grandmothers who buy lunch will be;
[tex]70+35=105[/tex]
Hence the ratio;
[tex]105:150[/tex]
also, the next column;
[tex]105+35=140[/tex]
For all grandmother, add 50 to 150
[tex]50+150=200[/tex]
Hence, the ratio equals;
[tex]140:200[/tex]
The next column for grandmothers who buy lunch;
[tex]140+35=175[/tex]
For all grandmother;
[tex]200+50=250[/tex]
The ratio;
[tex]175:250[/tex]
About 200
