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| 1. |
If 3nc2 = 2nc1 find n |
| Answer» FIND n, if 2n C 3 : n C 2 =52:3 n C 2 2n C 3 = 352 ∴ 2n(n−1) 3×2×12n(2n−1)(2n−2) = 352 ∴ 3×2×1×n(n−1)2n(2n−1)2(n−1) ×2= 352 ∴ 34(2n−1) = 352 ∴4(2n−1)=52 ∴2n−1= 452 ∴2n−1=13∴2n=13+1∴2n=14∴n=7 | |