Hello there!
Answer: 1/13
1/13 would represent the amount of bananas in the basket.
There would be only 1 banana because it would complete he amount of fruits in the basket.
In the basket, we know that there are:
1 orange + 5 apples + 4 kiwis + 2 pears = 12
That would be 12 fruits, but there are suppose to be 13 fruits, which means that the remaining 1 fruit would be a banana.
So, that means that the amount of bananas in the basket is 1 out of 13, or 1/13.
I hope this helps!
Best regards,
MasterInvestor