How many three-digit numbers greater than 600 can be formed
by using the digits 4, 5, 6, 7, 8?
Answers
Answered by
3
678 786 867 864 865 687 657 645 654 647 657 648 658 876 875 874 845 854 856 865 867 785 784 756 754 746 748 758 768
Answered by
10
digits are 4,5,6,7,8 for number to be greater than 600 at the hundred place 6,7,8 appear and this can be done 3 ways .
for remaining tow places we choose two number from remaining four digits. this can be done 4C2 ways = 4!/(2!2!) = 6 and two number can be interchanged by 2! = 2 ways .
so total numbers which is greater than 600 are = 2*3*6 = 36.
if you can not understand please ask.
for remaining tow places we choose two number from remaining four digits. this can be done 4C2 ways = 4!/(2!2!) = 6 and two number can be interchanged by 2! = 2 ways .
so total numbers which is greater than 600 are = 2*3*6 = 36.
if you can not understand please ask.
Similar questions