Answer:
6
Explanation:
We know the second number has to more than four, otherwise we can't subtract 7. But, if you calculate, 8 would be far too big. A number in between 4-8, 6.
The double of 6 is 12. 12-7=5.
This is showing the first number would be 5 and the second 6.
The third is one more than their sum. 5+6=11+1=12.
So finally adding, 11+12=23.