From statement A

Consider the individual contributions of "n" members be a,b,c,d...n

so total AM is 505210/n

Now total contribution increased to 1225890

therefore new AM is 1225890/n

percentage increase = 42.65% (Assuming the no of members remained same)

but since we don't know anything about the no of members we can't be sure. hence insufficient.

statement 2

Clearly Insufficient.

combining 1 and 2

Sufficient.

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