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In the problem below, AB, CD, and EF are two-digit numbers, where A, B
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06 Oct 2021, 05:30
06 Oct 2021, 05:30
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55%
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In the problem below, AB, CD, and EF are two-digit numbers, where A, B, C, D, E and F represent distinct digits from 1 to 9.
Is F prime?
A B
+ C D
______
E F
(1) B and D are consecutive integers.
(2) C = 8.
Is F prime?
A B
+ C D
______
E F
(1) B and D are consecutive integers.
(2) C = 8.
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In the problem below, AB, CD, and EF are two-digit numbers, where A, B
[#permalink]
06 Oct 2021, 06:02
06 Oct 2021, 06:02
(1) B and D are consecutive integers.
Hence the following combinations are possible
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
5,6 = 11 (Prime)
Here we get both prime and non prime hence insufficient
(2) C = 8.
If C is 8 then A has to be 1 with no carry over from ones digits. In that case the below combinations for B and D are valid
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
For the above combination it is not sufficient
Even combining, we get prime and non prime numbers for F hence Option E
Hence the following combinations are possible
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
5,6 = 11 (Prime)
Here we get both prime and non prime hence insufficient
(2) C = 8.
If C is 8 then A has to be 1 with no carry over from ones digits. In that case the below combinations for B and D are valid
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
For the above combination it is not sufficient
Even combining, we get prime and non prime numbers for F hence Option E
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Re: In the problem below, AB, CD, and EF are two-digit numbers, where A, B
[#permalink]
06 Oct 2021, 06:40
06 Oct 2021, 06:40
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sanjitscorps18 wrote:
(1) B and D are consecutive integers.
Hence the following combinations are possible
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
5,6 = 11 (Prime)
Here we get both prime and non prime hence insufficient
(2) C = 8.
If C is 8 then A has to be 1 with no carry over from ones digits. In that case the below combinations for B and D are valid
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
For the above combination it is not sufficient
Even combining, we get prime and non prime numbers for F hence Option E
Hence the following combinations are possible
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
5,6 = 11 (Prime)
Here we get both prime and non prime hence insufficient
(2) C = 8.
If C is 8 then A has to be 1 with no carry over from ones digits. In that case the below combinations for B and D are valid
1,2 = 3 (Prime)
2,3 = 5 (Prime)
3,4 = 7 (Prime)
4,5 = 9 (Non-Prime)
For the above combination it is not sufficient
Even combining, we get prime and non prime numbers for F hence Option E
Be careful. If A = 1, B = 4, C = 8 and D = 5, then the sum is 99, and we're told A, B, C, D, E and F represent distinct digits from 1 to 9.
