Answer:
a) Peter babysits a total of 6 days each week.
b) Peter babysits either Saturday or Sunday.
c) Peter babysits 80% of the days Monday through Friday.
d) Peter babysits 90% of the total days each week.
Step-by-step explanation:
1. Peter babysits his sister on Monday and Friday.
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.