Latest TCS Aptitude Question SOLUTION: How many 6 digit telephone numbers can be formed if each number starts with 35 and no digit appears more than once? Option 1) 720 2) 360 3) 1420 4) 1680

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(#M40134199) TCS Numerical Ability question Keep an EYE

How many 6 digit telephone numbers can be formed if each number starts with 35 and no digit appears more than once?


Option
1) 720
2) 360
3) 1420
4) 1680

Asked In TCS nagaraj (9 years ago)

Unsolved Read Solution (22)

Is this Puzzle helpful?   (63)   (40) Submit Your Solution Permutation and Combination

Read Solution (22) :

arun gupta  (9 years ago)

3 and 5 are already used , so the remaining no's left are 8 so , now in next step we will select 4 numbers from 8 and this can be done by 8C4* 4! ( 4! these selected 4 digits can be arranged in factorial 4 ways )
ans = 70*12= 1680

Is this solution Helpfull? Yes (8) | No (2)  

Darshit Pathak  (8 years ago)

we have to make 6 digit number...from which 2 digits are already given.so we are left with 4 digits and numbers from 0-9(exept 3 & 5)
so we have to find number of ways to arrange 8 numbers (i.e. 0,1,2,4,6,7,8,9) in to make 4 digit number..so that 8P4=8! / 4! = 1680.

Is this solution Helpfull? Yes (8) | No   

saisandeep  (9 years ago)

1*1*8*7*6*5 = 1680

Is this solution Helpfull? Yes (4) | No (1)  

naveen nandi  (9 years ago)

6 digits telephone no can be formed by 10 digits, but form qustn each no start with 35 so we have 8 digits remaining so 4 places can be formed in 8*7*6*5=1680.

Is this solution Helpfull? Yes (3) | No   

Sakshi Agarwal  (8 years ago)

8*7*6*5=1680

Is this solution Helpfull? Yes (1) | No   

chamu  (9 years ago)

we have to fill 6 digit number
35 - - - - so 8×7×5×6=1680

Is this solution Helpfull? Yes | No   

NILESH ASHOK DOKR  (8 years ago)

And is1680
bcoz let consider first. Two digit const as 35 and arrangement of remain 4 digit from 01246789 using 7p4..
So ans=7*6*5*4=1680

Is this solution Helpfull? Yes | No (1)  

kavana j  (8 years ago)

in 6 places like _ _ _ _ _ _ ,starting will be always 35 so that,digit will be from 0-9 here already 3 and 5 are present so remaining possible are 8!*7!*6!*5!=1680 i.e option:(4)

Is this solution Helpfull? Yes | No   

SURAJ GUPTA  (8 years ago)

As the no start with 35 so
remaining no left is 8
so 8*7*6*5*1=1680

Is this solution Helpfull? Yes | No   

prabhat ranjan mishra  (8 years ago)

1680 is riht

Is this solution Helpfull? Yes | No   

soundarya krishnamurthy  (8 years ago)

1680
of 6 numbers 2 numbers are already given and remaining 8 numbers are there. so,8*7*6*5=1680

Is this solution Helpfull? Yes | No   

Maheswari  (8 years ago)

720
6 digit number.. 6!

Is this solution Helpfull? Yes | No (1)  

raviteja  (8 years ago)

we have 8 digits left to be placed in 4 places this can be done in'8 * 7 * 6 * 5 = 1680

Is this solution Helpfull? Yes | No   

Rabiraj Banerjee  (8 years ago)

if each number starts with 35 so 1st 2 places are booked and remaining 4 places has to be filled with 8 numbers.This can be done in 8P4 ways =1680 ways

Is this solution Helpfull? Yes | No   

sandiip roy  (8 years ago)

There is 10 numbers from which we have to select 6numbers from the 6numbers 3 and 5 already took the place of 1st and 2nd (012_4_6789) 3 5 _ _ _ _ the next 4numbers can be select out of 8numbers by using MNP rules hence 8*7*6*5=1680

Is this solution Helpfull? Yes | No   

Deepak kumar  (8 years ago)

3 5 r fix 8 * 7 * 6*5 =1680
__ __ __ __ __ __

Is this solution Helpfull? Yes | No   

Arindam Animesh  (8 years ago)

For a 6 digit no. First 2 digits are 35 hence to fill the 3rd digit we have 8 options , to fill the 4th one 7 and so on.

Therefore, the answer will be
8*7*6*5 = 1680

Is this solution Helpfull? Yes | No   

sheenu garg  (8 years ago)

1680 since first two places can be filled with one way then 3 place with 8 then 7 then 6 then 5
so 1*1*8*7*6*5=1680

Is this solution Helpfull? Yes | No   

janmanjay banerjee  (8 years ago)

(0-9)= 9 digits. 35 fixed. Remaining digits=8. nos to be selected =4. 4 places can b filled in 4! ways
SO...8c4*4!=70*24=1680

Is this solution Helpfull? Yes | No   

Aayush Verma  (7 years ago)

4 -> 1680
as the first two digits are already reserved so remaining four places can be filled in 8*7*6*5 ways
so ans is 1680

Is this solution Helpfull? Yes | No   

Manisha Roy  (7 years ago)

1680
1*1*8*7*6*5=1680

Is this solution Helpfull? Yes | No   

Praveen  (6 years ago)

1680
8*7*6*5

Is this solution Helpfull? Yes | No   

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