72
68.
9 and 36
The largest prime less than 20 is 19. The largest prime over 60 is 61. The sum of these two numbers is 80.
I think you are looking for 36
80
77.
80 because 16*5 = 80
79 + 73 = 152
80 cm is less.
80% less than 90 = 20% of 90 = 18
-56
80 is smaller than 666.