Answer:
84ways
Step-by-step explanation:
This is a problem on combination. Combination has to do with selection. For example if r objects are to be selected from a pool of n objects, this can be done in nCr ways.
nCr = n!/(n-r)!r!
9C3= 9!/(9-3)!3!
9C3= 9!/(6)!3*2*1
9C3= 9*8*7*6!/(6)!6
9C3= 9*8*7*/6
9C3= 9*8*7*/6
9C3= 504/6
9C3= 84ways
Answer:
DF,DE,EF
Step-by-step explanation:
c-de=9cm; ef=15cm hope this helps