再请教两道prep数学题

1. if t is a positive integer and r is the remainder when t^2+5t+6 is divided by 7, what is the value of r?

(1).when t is divided, the remainder is 6;

(2).when t^2 is divided, the remainder is 1;

答案是a;

2.  a computer chip manufacturer expects the ratio of the number of defective chips to the total number of chips in the future to equal to corresponding ratio for shipments S1, S2, S3 and S4 combined, as shown in the table. What is the expected number of the defected chip in a shipment of 60,000 chips.

快上考场了，开始模考，数学不敢大意，请大牛帮忙解答，感激不尽~~

补充一下，第一道是DS题目，第二道的选项如下：a. 14; b. 20; c.22; d.24. e.25. 答案是20。谢谢~~