Answer:
16
Step-by-step explanation:
From the first equation, I can infer that one pair of boots equals 10 because 10+10+10=30. Also, I can infer that just one boot equals 5 because there are 6 boots in total and 5+5+5+5+5+5=30
From the second equation, I can infer that one boy equals 5 because 2 boys which equal 10 plus one pair of boots which equals 10 is 20.
From the third equation, I can infer that one pair of ribbons is 4 because the boy equals 5 and 13-5=8. There are two pairs of ribbons so 8/2=4. I can also infer that just one ribbon is 2 because 8 divided by 4 individual ribbons is 2.
So, for the last equation, it would be 5+9+2 which the answer would equal 16. The one boot that would equal 5 plus the boy and 2 individual ribbons he's holding in his hands would equal 9 plus one ribbons which would equal 2 would all equal 16.
Hope this is helpful.