(a) 7!/(3!2!) = 420
(b) If 3,4 are used, that leaves 5!/3! = 20
(c) divisible by 5 means that 3,4,5 are used, leaving 4!/3! = 6
(2) divisible by 2 means that 2,3,4 are used, leaving 4!/2! = 12
(a):how many digit number can be formed with the digit 2,2,2,3,3,4,5
(b):how many of these are greater than 3400000
(c):how many are greater than 3400000 and are divisible by 5
(d):how many are greater than 3400000 and are even
????
2 answers
Thanks steve