I think this is a proportion problem. Since the 1st question focuses on A and B, the proprtion will be:
$${\frac{{\mathtt{A}}}{{\mathtt{B}}}} = {\frac{{\mathtt{A}}}{{\mathtt{B}}}}$$
The ratio from A to B is 3: 7... and $5096 was given to A... sooo....
$${\frac{{\mathtt{A}}}{{\mathtt{B}}}} = {\frac{{\mathtt{A}}}{{\mathtt{B}}}} = {\frac{{\mathtt{3}}}{{\mathtt{7}}}} = {\frac{{\mathtt{A}}}{{\mathtt{5\,096}}}}$$
To find A, you would cross multiply... 7 • A = 7a and 5096 • 3 = 15288... soo...
$${\mathtt{7}}{A} = {\mathtt{15\,288}}$$
Then you would divide both sides by 7...
$${\mathtt{A}} = {\frac{{\mathtt{15\,288}}}{{\mathtt{7}}}}$$
$${\mathtt{A}} = {\mathtt{2\,184}}$$
Therefore, the answer to (a) is $2,184.