21. If he travels the same distance each day for 11 days straight and on the 12th day he travels 7 miles extra...and if he traveled 91 miles in total, the total distance that he would have traveled if he hadn't traveled those extra 7 miles would have been 91 - 7, and then to discover the average distance traveled per day you divided it by 12.
So the expression would be (91 - 7)/12 which is C
22. If you are subtracting 1 from 5, you are taking 1 away from 5. So you get 5-1. Then you are multiplying the difference (5 - 1) by 8, so (5 - 1) *8 and then you add 15 to it. The answer is D and not A because in A you are only multiplying -1 by 8, instead of the difference.
23. Using BODMAS (Brackets,Orders,Divide,Multiply,Add,Subtract)
You do the brackets first, so you do the 4+2 first =6
Updated equation: 2 *(36 - 4(6))
you then multiply 4 by 6 =24
Updated equation: 2 *(36 - 24)
You then subtract 24 from 36= 12
Updated equation: 2*(12)
Final answer you multiply 2 by 12 to get 24
Answer= 24 which is A in the sheet