Which of these two -digit numbers is much less common than four others?

The simplest question, although at first it did not seem like that, some numbers, I have already prepared for complex calculations and thoughts, because this question is for senior schoolchildren. But there is nothing to solve here, in fact,. Behind…day – if we substitute all five of our two -digit numbers in place, then four of them will get up perfectly and the phrase will sound correctly and harmoniously: in 14, 27, 35, 60 days. But: for 24 days something is already not that, the number 24 goes well with the word ‘day’, for example, if there were four days, we would say: for four days, and with the number 24 we cannot do so, therefore, the correct answer: 24.