urgent p&c

the number of four digits having only two consecutive digits identical is ??

5 Answers

996

Swarna Kamal Dhyawala ·2013-03-19 11:42:30

manish sir plzz help?

1357

Manish Shankar ·2013-03-19 22:41:42

take the two consecutive numbers as one number and proceed

1133

Sourish Ghosh ·2013-03-19 23:16:05

Is the answer 3x9x9x8 + 9x9 ?

229

Dwijaraj Paul Chowdhury ·2013-03-20 03:27:04

the answer should be 9*8*3=216

1357

Manish Shankar ·2013-03-23 05:17:08

Take two digits as X

so we have to form number XYZ

which can be done in 9*9*8*3 ways

Now let the two digits are repeating as X and Y

so the number will be XY
no. of ways is 9*9

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