## Combinatorics

For students upto class 5 (age upto 12)
Akash7
Posts: 5
Joined: Thu Mar 15, 2018 10:31 am
Location: Dhaka

### Combinatorics

In how many ways can COMPUTER be spelled by moving either down or diagonally to the right showed in the figure below??
Attachments
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Ragib Farhat Hasan
Posts: 37
Joined: Sun Mar 30, 2014 10:40 pm

### Re: Combinatorics

The answer should be 14.

NABILA
Posts: 27
Joined: Sat Dec 15, 2018 5:19 pm
Location: Munshigonj, Dhaka

### Re: Combinatorics

HOW??????????????????????

NABILA
Posts: 27
Joined: Sat Dec 15, 2018 5:19 pm
Location: Munshigonj, Dhaka

### Re: Combinatorics

HOW??????????????????????

samiul_samin
Posts: 1004
Joined: Sat Dec 09, 2017 1:32 pm

### Re: Combinatorics

Count carefully acclrding the question.

NABILA
Posts: 27
Joined: Sat Dec 15, 2018 5:19 pm
Location: Munshigonj, Dhaka

### Re: Combinatorics

I still can't understand.
Wãlkîñg, lõvǐñg, \$mīlïñg @nd lìvíñg thě Lîfè

SMMamun
Posts: 56
Joined: Thu Jan 20, 2011 6:57 pm

### Re: Combinatorics

If repeated letters distract you, replace these in the following way, because the question basically asks you to choose and count properly:

A
B C
D E F
G H I J

From A, you have 2 choices: AB and AC (one down and the other right-down diagonally).
From each of AB and AC, you have also 2 choices: ABD, ABE and ACE, ACF. Total count up to the third row is, therefore, 4 or (2 × 2)
From each of ABD, ABE, ACE, and ACF, you have also 2 choices.

Can you see a pattern now and complete?