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A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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Updated on: 20 Jul 2018, 22:12
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Permutation and Combination  Practice Question #33A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,9 according to the following pattern. The first digit must be 2 or 4, 3rd digit must be a multiple of 3 and no two consecutive digits should be same. How many different codes are possible. Options a) 2,016 b) 3,888 c) 4,608 d) 5,184 e) 6,236 To solve Question 1: Question 1To solve Question 2: Question 2To read our article: Must Read Articles and Practice Questions to score Q51 !!!!
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A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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Updated on: 23 Jul 2018, 04:53
Solution Given:• A fivedigit code uses the digits 0,1,2,3,4,5,6,7,8,9. • The first digit must be 2 or 4 • 3rd digit must be a multiple of 3 • No two consecutive digits should be same
To find:• The number of different codes possible. Approach and Working: Let the 5digit number is abcde. • Ways to fill ‘a’ = 2(2 or 4)
• Ways to fill ‘c’ = 4 (0,3,6,9)
• Hence, we filled two different digits in ‘a’ and ‘c’.
o So, out of 10 digits, b cannot take 2 digits. o Thus, ‘b’ can be filled in 8 ways. • Now, ‘d’ can be filled in 9 ways as similar digit cannot be in ‘c’ and ‘d’.
• Similarly, ‘e’ can be filled in 9 ways. Thus, total ways to fill= 2*8*4*9*9= 5184 Hence, the correct answer is option d. Answer: d
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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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20 Jul 2018, 08:12
A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,9 according to the following pattern. The first digit must be 2 or 4, 3rd digit must be a multiple of 3 and no two consecutive digits should be same. How many different codes are possible.
1st cell  2 options (2,4)  the first digit must be 2 or 4 3rd cell  4 options (0,3,6,9)  multiples of 3 2nd cell  8 options  can not be surrounded by the same digits that are located in cells 1 and 3, so we have to pick from 102=8 4th cell  9 options 5th cell  9 options
2*8*4*9*9 = 5,184
Answer D



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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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21 Jul 2018, 03:14
EgmatQuantExpert wrote: Permutation and Combination  Practice Question #33A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,9 according to the following pattern. The first digit must be 2 or 4, 3rd digit must be a multiple of 3 and no two consecutive digits should be same. How many different codes are possible. Options a) 2,016 b) 3,888 c) 4,608 d) 5,184 e) 6,236 To solve Question 1: Question 1To solve Question 2: Question 2To read our article: Must Read Articles and Practice Questions to score Q51 !!!! code is of the form abcde let's fill the constraints first: a can be filled in 2 ways (2 or 4) c can be filled in 4 ways (0,3,6, or 9) b can be filled in 8 ways (can't be same as a or c) d can be filled in 9 ways (can't be same as c) e can be filled in 9 ways (can't be same as d) total = 2*4*8*9*9 = 5184.
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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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21 Jul 2018, 21:12
IMO it should be 2*8*3*9*9= 3888 (B) I do not understand how 0 can be considered a multiple of 3. In that way 0 is multiple of each and every number.



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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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22 Jul 2018, 03:00



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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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23 Jul 2018, 04:57



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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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28 Aug 2018, 09:06
EgmatQuantExpert wrote: Solution Given:• A fivedigit code uses the digits 0,1,2,3,4,5,6,7,8,9. • The first digit must be 2 or 4 • 3rd digit must be a multiple of 3 • No two consecutive digits should be same
To find:• The number of different codes possible. Approach and Working: Let the 5digit number is abcde. • Ways to fill ‘a’ = 2(2 or 4)
• Ways to fill ‘c’ = 4 (0,3,6,9)
• Hence, we filled two different digits in ‘a’ and ‘c’.
o So, out of 10 digits, b cannot take 2 digits. o Thus, ‘b’ can be filled in 8 ways. • Now, ‘d’ can be filled in 9 ways as similar digit cannot be in ‘c’ and ‘d’.
• Similarly, ‘e’ can be filled in 9 ways. Thus, total ways to fill= 2*8*4*9*9= 5184 Hence, the correct answer is option d. Answer: d egmat I have a doubt in digit abcde d can also take the value of e right? d is sandwiched between c and e ( as b is sandwiched between a and c) . de is also a consecutive pair so shouldn't the no of ways to fill d be 8? and that of e be 9



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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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15 Oct 2018, 07:01



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Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8,
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15 Oct 2018, 07:05




Re: A fivedigit code for certain locks uses the digits 0,1,2,3,4,5,6,7,8, &nbs
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15 Oct 2018, 07:05






