Solving Significant Digit Problems with Varying Order of Magnitude

[Irid]

I have reasons to believe that my question asks to write the answer with 3 significant digits (i.e. the given numbers are with 3 digits). But there are several figures to be worked out, so I list them (for example):

3.45
3.89
7.90
...
10.23 or 10.2 (or even 10.20)?

The problem is that the order of magnitude of the answers varies and I don't know what to do: write 4 significant digits (although I should know only 3) or stick with only 3, but then the number digits after the decimal point is different.

 

[Defennder]

It should be 10.2 10.20 appears to imply that you measured down to 100th decimal place of accuracy. 10.23 is 4 sig fig.