Respuesta :

1a. 3 7/12 is very close to 3 6/12 which is 3 1/2, so 1a is correct.

1b. 2 5/6 is close to 3, so 1b is also correct.

1c. 3 1/2 + 3 = 6 1/2. 1c is also correct.

The three circled choices are correct.