0.8
you find how much he needed so:
24*0.3=7.2
than 8 he had , so whats left over
8-7.2=0.8
Answer:
84
Step-by-step explanation:
Combinations
nCr
n (objects) = 9
r (sample) = 3
9C3
n! / r! (n – r)!
9! / 3! (9 – 3)!=
9! / (3! * 6!)=
9*8*7*6!/ (3! * 6!)=
6! cancels out
9*8*7/3*2*1=
3*4*7=
12*7=
84
