Answer:
2ft
Step-by-step explanation:
5 x 10=50
7 x 12= 84
5+2=7 and 10+2=12
The answer is c. 
a.
(2.2≠5.11) (2.2 is not equal to 5.11)
b.
or 0.625 (0.625≠5.11) (0.625 is not equal to 5.11)
c.
(5.11=5.11) (5.11 is equal to 5.11)
Therefore c is the answer
It's c. all of them added up is 41/24 which converts to 1 17/24.
Im gonna take an educated guess on this. for the first part only one element has an outershell filled completely. but if they want two elements put chlorine. to lose electrons is probably helium to gain is magnesium. and the last one is lithium and helium because they're small and don't have allot of atomic mass