Call Brianna is B,Shanita is S.

B+S=24.00

B-2S=3.00

2B-2S=6.00

 B is:(24.00 x 2)+6.00}:2:2=13.50

S is:24.00-13.50=10.50

Deduced Brianna has 10.00 more than Shanita

Because the calculator is down,the calculator will be:

(12x3)+(4x2) become (12:3)-(4:2)=4-2=2.The answer is A