Answer:
0.5lb cereal squares, 0.75 lb nuts
Explanation:
1lb nuts = $7
multiply each side by 1/2 (whatever you do to one side, you do to the other),
0.5lb nuts = $3.5
1lb cereal squares = $4
multiply each side by 3/4 (whatever you do to one side, you do to the other),
0.75lb cereal squares = $3
0.5lb nuts + 0.75lb cereal squares = 3.5 + 3 = $6.5