Level 3
Find the possible value(s) of Y in ascending order if Y is a 2-digit odd number that is smaller than 30, a multiple of 3 and also a factor of 45.
Level 3
I am an even number. When 1 is added to me and I am rounded off to the nearest ten, I become 660. When 1 is subtracted from me and I am rounded off to the nearest ten, I become 650. What number am I?