Question
What are the missing numbers?
2020, 2040, (a)         , 2080, (b)         , 2120
2 m
(a)

Click button first when a symbol is required. X

(b)

Click button first when a symbol is required. X

What are the missing numbers?
2020, 2040, (a)         , 2080, (b)         , 2120