64. (3 1/2 - 2 3/4) * (1 1/6 - 1/12)

64. (3 1/2 - 2 3/4) * (1 1/6 - 1/12) = (7/2 - 11/4) * (7/6 - 1/12) = (14/4 - 11/4) * (14/12 - 1/12) = 3/4 * 13/12 = 39/48 = 13/16

Ответ: 13/16