Ages of the tennis-playing mother and daughter? (5,7)

'tennis-playing mother and daughter?' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'ages of the' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
This explanation may well be incorrect...

Can you help me to learn more?