Word problems and computation

1. 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 =

40 45 50

2. Toy 1, 2, and 3 weigh 100kg. Toy 1 and 3 weigh 60.5kg. How much does toy 2 weigh?

39.5kg 40.5kg 40kg

Table data

Look at the table below.

Input Output
1 3
2 5
3 3. 5 7 9
4 9
4. 5, 10 6, 11 5, 11 See the left.

5. If the pattern keeps going on, what will be the next 2 rows?

Input Output
6 13
7 15
Input Output
6 12
7 14