Mathematics - Permutation & Combination Question with Solution | TestHub

MathematicsPermutation & CombinationnPr & nCrMedium2 minPYQ_2023

MathematicsMediumsingle choice

How many different nine digit numbers can be formed from the number 223355888 by rearranging its digits so that the odd digits occupy even positions?

Options:

Answer:

Solution:

$X - X - X - X - X$ . The four digits 3, 3, 5,5 can be arranged at $(-)$ places in $\frac{4 !}{2 ! 2 !} = 6$ ways. The five digits $2, 2, 8, 8, 8$ can be arranged at $(X)$ places in $\frac{5 !}{2 ! 3 !}$ ways $= 10$ ways
Total no. of arrangements $= 6 \times 10 = 60$ ways

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

⏱ 2mℹ️ Source: PYQ_2023

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