What would the output of a 7447 IC be if the input was above 9?
You have your 7447 and 7490 mixed up. The 7490 is the decade counter. The 7447 is a "BCD-TO-SEVEN-SEGMENT DECODER/DRIVER". Here is the datasheet for 7447. If you look on page 3 you will see a diagram of the segment outputs for binary inputs above 9.