The-number-of-five-digits-can-be-made-with-the-digits-1-2-3-each-of-which-can-be-used-atmost-thrice-in-a-number-is-

Question Number 171012 by mr W last updated on 06/Jun/22

The number of five digits can be made

with the digits 1, 2, 3 each of which can

be used atmost thrice in a number is

Commented by otchereabdullai@gmail.com last updated on 07/Jun/22

nice question + nice solution!

Answered by mr W last updated on 06/Jun/22

a = n u m b e r o f d i g i t s 1 i n t h e n u m b e r

b = n u m b e r o f d i g i t s 2 i n t h e n u m b e r

c = n u m b e r o f d i g i t s 3 i n t h e n u m b e r

0 ⩽ a, b, c ⩽ 3

a + b + c = 5

c o e f f i c i e n t o f x^{5} i n 5! {(1 + \frac{x}{1!} + \frac{x^{2}}{2!} + \frac{x^{3}}{3!})}^{3}

i s 210 . \Rightarrow 210 n u m b e r s

Commented by Tawa11 last updated on 06/Jun/22

Great sir

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