Deepak’s dalliance with digits

By

KT Rajagopalan

The question:

‘Tell me the sum of the digits of the highest 9-digit number, the product of whose digits is 9! (To refresh your memory, ‘9!’ – pronounced factorial 9 -  is, 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9)’ asked the teacher.

‘Why did he ask such a simple question?’ thought Deepak. ‘The number could be none other than ‘987654321’ and he wrote down ‘45’ as the answer.

But, soon he had second thoughts. Perhaps, there was a catch? Deepak pondered over the problem. Suddenly, he erased the answer ‘45’, and wrote down the correct answer. What was that? It was one of the following:

(a) 55           (b) 50           (c) 48           (d) 39           (e) 49    

Would you like a hint?

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