题型:解答题 题类:常考题 难易度:普通
Two Trips
Jack brought a small plane and began to fly it. He soon became excited and made his plane all kinds of tricks.
Jack had a friend,named Tom. One day Jack said to him,“I will pick you up in my plane.““I will be glad to.'answered Tom. They went up,and Jack flew around for half an hour and did all kinds of tricks in the air. Then they came down. Tom was to be back safely,and said to Jack,“Well,Jack,thank you very much for those two trips in your plane.“Jack was very surprised and asked,“Two trips?““Yes,my first and my last.'an﹣swered Tom.
根据上文填表
出现字母的个数 | 100 | 150 | 200 | 250 | 300 | 350 | 400 |
出现字母a的频数 | |||||||
出现字母a的频率 | |||||||
出现字母b的频数 | |||||||
出现字母b的频率 |
时间(小时) |
频数(人数) |
频率 |
2≤t<3 |
4 |
0.1 |
3≤t<4 |
10 |
0.25 |
4≤t<5 |
a |
0.15 |
5≤t<6 |
8 |
b |
6≤t<7 |
12 |
0.3 |
合计 |
40 |
1 |
年龄/岁 | 13 | 14 | 15 | 16 |
人数/人 | 4 | 5 | 4 | 3 |
试题篮