$\frac{1}{2}\times \frac{1}{4}+\frac{3}{4}\times \frac{1}{2}$ ＝（   ）

(Some classmates are talking about their weekend.)

    Linda: I stayed at home and studied over the weekend. I studied for my English test on Saturday. Yesterday I wrote a geography paper. In the evening I talked to my pen pal (笔友) on the phone. What did you do?

Tim: I had a good time. On Saturday morning I played tennis, in the afternoon I went to the beach, and in the evening I went to Nancy's birthday party. On Sunday I went to the mountains with my friends.

Mary: Oh, your weekend was great. But mine was boring. I stayed at home the whole (全)weekend. I cleaned my room and washed my clothes. I even watered the flowers. And only in the evening I watched TV for a short time. Did you go out, Dave?

Dave: No, I didn't. I stayed at home and watched TV on Saturday. Yesterday I watched a movie on TV, Fearless. It was very exciting.