Mathematics · 2018
JEE Main · 15 April 2018, Shift 1 · Q66
n-digit numbers are formed using only three digits 2, 5 and 7. The smallest value of n for which 900 such distinct numbers can be formed, is:
n-digit numbers are formed using only three digits $\displaystyle 2$, $\displaystyle 5$ and 7. The smallest value of n for which $\displaystyle 900$ such distinct numbers can be formed, is :
Official answer
(2)
$\displaystyle 7$
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JEE Main 2018 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.