5C1+5C2+5C3+5C4+5C5 is equal to
30
31
32
33
5C1+5C2+5C3+5C4+5C5=5C1+5C2+5C2+5C1+5C5=2×5C1+2×5C2+5C5=2×5+2×5!2!3!+1=10+20+1=31