In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: point ( m , n ) is on the circle represented by m ^ 2 + n ^ 2 = 10 , and m , n are integers . how many such points are possible ? 
Options: a ) 0 , b ) 2 , c ) 4 , d ) 6 , e ) 8
e

Problem: 8597 - ? = 7429 - 4358 
Options: a ) 3567 , b ) 6424 , c ) 6835 , d ) 5526 , e ) none of these
d

Problem: a solution of 90 litres contains milk and water in the ratio 7 : x . if 10 litres of water is added to the solution , the ratio becomes 3 : 2 , find the value of x ? 
Options: a ) 2 , b ) 1.5 , c ) 3.5 , d ) 2.5 , e ) 3

c