JAMB - Mathematics (2008 - No. 43)
Find the number of ways of selecting 6 out of 10 subjects for an examination
128
216
215
210
Explicação
\(^{10}C_6 = \frac{10!}{(10-6)!6!}\)
= \(\frac{10!}{4!6!}\)
=\(\frac{10\times 9\times 8 \times 7 \times 6!}{4\times 3\times 2\times 1 \times 6!}\)
= 210.
= \(\frac{10!}{4!6!}\)
=\(\frac{10\times 9\times 8 \times 7 \times 6!}{4\times 3\times 2\times 1 \times 6!}\)
= 210.