Home
PYQ PracticeFree
JEE Rank Predictor
Answer Key

Mathematics - Permutation & Combination Question with Solution | TestHub

MathematicsPermutation & CombinationnPr & nCrMedium2 minPYQ_2018

MathematicsMediumsingle choice

$n$ - 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

Options:

Answer:

Solution:

Required $n$ digit numbers is $3^{n}$ as each place can be filled by $2, 5, 7$ . So smallest value of $n$ such that $3^{n} > 900$ . Therefore $n = 7$ .

Stream:JEESubject:MathematicsTopic:Permutation & CombinationSubtopic:nPr & nCr

⏱ 2mℹ️ Source: PYQ_2018

Doubts & Discussion

Loading discussions...