$$7\times3=21$$~ $21+40=61$ 
Think Academy will hold a concert. The stage and seats have been set up. There are $$40$$ benches that can only seat one people each, and there are $$7$$ benches that can seat three people each ,How many people can all the chairs and benches hold? 
Options:
a. $$40$$ 
b. $$54$$ 
c. $$61$$ 
d. $$70$$ 