Quant Question Of The Day: 58
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Numbers
Which of the following numbers are prime numbers?
A. 2208 + 1
B. 2210 + 1
C. 2205 + 1
1. A and B
2. A and C
3. B and C
4. None of the above .
A( 2n + 1) + B(2n + 1) is always divisible by ( A + B).
2208 + 1 = (216)13 + 113 this number is divisible (216 +1), similarly others.
Hence, None.
1. A and B
Since none of the above can be written in 6k+1 form (3 missing) it is option 4
Prime no.s are of the form 6k+/-1
Here none of them is of the form of prime no.
Hence option 4
A and C