My first is in reason and also in rhyme
My second in quick and, yes, it’s in time
My third is in dinner, but, no, not in tea
The fourth’s in dessert, never pudding, you see
My fifth’s in solution, see, it’s there in dissolve
My last is in ending, as problems resolve
My whole is the challenge, as set by teaotter 
The answer, a conundrum, so, have you got ‘er?