Question
if repeated digits are not allowed the number of four digit even numbers that can be formed from the digits 0,1,5,6,7,8,9 is
Answers
oobleck
6{08}x{80}: 2*5 = 10
6x{08}{80}: 5*2 = 10
same for leading 8: 20
{1579}<odd><odd>{068}: 4*3*2*3 = 72
{1579}<odd><even>{068}: 4*3*3*2 = 72
same for {1579}<even><odd>{068}: 72
Looks like 256 in all
Double-check to see whether I missed something.
6x{08}{80}: 5*2 = 10
same for leading 8: 20
{1579}<odd><odd>{068}: 4*3*2*3 = 72
{1579}<odd><even>{068}: 4*3*3*2 = 72
same for {1579}<even><odd>{068}: 72
Looks like 256 in all
Double-check to see whether I missed something.