Wally asked Joy how old she was. Joy said to him that she would give him three clues and see if he could guess her age. Joy wrote down the clues and let Wally make a guess.

a. My age is between 18 and 35

b. My age is a multiple of 3.

c. My age is an odd number.

d. The digits of my age are repeated.

How old is Joy?
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