请教PREP-MATH的DS好题三道！！！！

1.Malik's recipe for 4 servings of a certain dish requires 1
                         cups of pasta.  According to this recipe, what is the number of cups of pasta that Malik will use the next time he prepares this dish?

(1)  The next time he prepares this dish, Malik will make half as many servings as he did the last time he prepared the dish.

(2)  Malik used 6 cups of pasta the last time he prepared this dish.

(1)  When x is divided by 6, the remainder is 2.

(2)  When x is divided by 15, the remainder is 2.

3 What was the percent increase in the population of City K from 1980 to 1990 ?

(1)  In 1970 the population of City K was 160,000

(2)  In 1980 the population of City K was 20 percent greater than it was in 1970, and in 1990 the population of City K was 30 percent greater than it was in 1970.\

烦请大家伙帮忙解答，谢谢