How many combinations of 7 in 10?

The number of combinations of 7 items taken from a set of 10 can be calculated using the formula for combinations, which is ( C(n, r) = \frac{n!}{r!(n-r)!} ). For 7 in 10, this is ( C(10, 7) = \frac{10!}{7!(10-7)!} = \frac{10!}{7!3!} = \frac{10 \times 9 \times 8}{3 \times 2 \times 1} = 120 ). Thus, there are 120 combinations of 7 in 10.