Which ordered pair is a solution to this equation? 3x + 7y = 13 a. (4, 1) b. (2, 1) c. (3, 1) d. (13, 2)

a) Peter babysits a total of 6 days each week.

False

b) Peter babysits either Saturday or Sunday.

True

c) Peter babysits 80% of the days Monday through Friday.

True.

d) Peter babysits 90% of the total days each week.

False

Explanation:

1. Peter babysits his sister on Monday and Friday.

that is 2 days

2. He babysits for his neighbor 40% of the days Monday through Friday.

40% of 5 days is 0.40 × 5 = 2 days

3. He babysits for his sister and his neighbor on different days.

Then, he babysits 2 + 2 = 4 days Monday through Friday.

4. On the weekend, Peter babysits 50% of the days.

That is one additional day, and makes a total of 5 days in a weak.

Statements:

a) Peter babysits a total of 6 days each week.

False: we calculated 5 days in a week.

b) Peter babysits either Saturday or Sunday.

True: since, on the weekends he babysits 50% of the days: that is one day which may be either Saturday or Sunday.

c) Peter babysits 80% of the days Monday through Friday.

80% of 5 is 0.8 × 5 = 4, which is what we calculated on the point 3 above. Then, it is true.

d) Peter babysits 90% of the total days each week.

90% of 7 is 0.9 × 7 = 6.3. On point 4 above, we calculated that he babysits 5 days in a week. Thus, this is false.