$^n{C_r} + {2^n}{C_{r - 1}}{ + ^n}{C_{r - 2}} = $
$^n{C_r} + {2^n}{C_{r - 1}}{ + ^n}{C_{r - 2}} = $
- A
$^{n + 1}{C_r}$
- B
$^{n + 1}{C_{r + 1}}$
- C
$^{n + 2}{C_r}$
- D
$^{n + 2}{C_{r + 1}}$
Similar Questions
If all the six digit numbers $x_1 x_2 x_3 x_4 x_5 x_6$ with $0 < x_1 < x_2 < x_3 < x_4 < x_5 < x_6$ are arranged in the increasing order, then the sum of the digits in the $72^{\text {th }}$ number is $............$.
If all the six digit numbers $x_1 x_2 x_3 x_4 x_5 x_6$ with $0 < x_1 < x_2 < x_3 < x_4 < x_5 < x_6$ are arranged in the increasing order, then the sum of the digits in the $72^{\text {th }}$ number is $............$.
- [JEE MAIN 2023]
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$^{2 n} C_{3}:^{n} C_{3}=11: 1$
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$^{2 n} C_{3}:^{n} C_{3}=11: 1$
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