Question 1: Method 1: 30 yuan rental fee is charged every month, and the call fee is charged at 0. 1 yuan per minute according to the accumulated call time; ..................... 1 point

Method 2: No monthly fee is charged, and the phone bill is charged at 0.2 yuan per minute according to the accumulated call time. ........................, two points.

Question 2: 33, 30; ? 38,40

Question 3: The two methods will charge the same amount; When the call time is less than 180 minutes, choose the second method to save money.

When the call exceeds 180 minutes, choose the first method to save money.

? (2) Call1:18+150× 0.1= 33 for 50 minutes.

Scheme 2: 150×0.2=30.

Call for 200 minutes according to Method 1: 18+200×0. 1=38.

Scheme 2: 200×0.2=40.

(3) If the call time is X minutes, the cost will be the same.

According to the equation, the score is:18+0.1x = 0.2x ... 3 points.

Fraction of solving equation: x =180 ……………………………………………………………………………………………………………………………………………….

Therefore, when talking for 180 minutes, the charges of the two methods are the same.

When the call time is known to be within 180 minutes, choose the second method to save money.

When the call exceeds 180 minutes, choose the first method to save money.