No table is provided.
"Guess and check" is a solution method suitable for multiple choice questions and other questions that don't have a simple and obvious method for obtaining a solution directly.
For problems of this sort, you can usually work them in your head by assuming all of the total comes from the least contributor. Here, that would be tomato packets at $3 each. Buying 9 packets will result in a total of $27, which is $4 short of the actual total. Now, consider how much more the radish packets are. they are $4 - $3 = $1 more for each packet. That is, the $4 shortfall in total cost can be made up by having four (4) radish packets in the mix.
Without "guess and check" you have found that Evita bought 4 packets of radish seeds.
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I suppose you could "guess and check" using ...
9 tomato + 0 radish : 9*$3 + $0 = $27
8 tomato + 1 radish : 8*$3 + 1*$4 = $28 . . . . up by $1. We need to go up 3 more
5 tomato + 4 radish : 5*$3 + 4*$4 = $31 . . . . the solution we want
