4. Your friend would be incorrect because their decimal is in the wrong place. Take the decimals out of it and think about it. Can 1 times 2 equal anything near 31? no, so it's not reasonable that your friend could multiply 1.2 X 2.6 and get anything near 31.2
5. It is more reasonable to say between 5 and 6 because even when you round both of the numbers up (3 X 2), you still only get 6.
Step-by-step explanation:
ill put it in the comments so I can get this to you faster.