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Fractal
- Master | Next Rank: 500 Posts
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1.If r is the remainder when the positive integer n is divided by 7, what is the value of r
1. when n is divided by 21, the remainder is an odd number
2. when n is divided by 28, the remainder is 3
The possible reminders can be 1,2,3,4,5 and 6. We have the pinpoint the exact remainder from this 6 numbers.
St 1: when n is divided by 21 ( 7 and 3) the remainder is an odd number.
But it cannot be 7, 3 or 9 . Hence the possibilities are : 1 and 5.
Hence there can be two remainders ,1 and 5, when divided by 7.
NOT SUFFICIENT
St 2: when n is divided by 28 the remainder is 3.
As 7 is a factor of 28, the remainder when divided by 7 will be 3
SUFFICIENT
MY QUESTION: Has anybody a rule to this statement above (bold)?
thx
1. when n is divided by 21, the remainder is an odd number
2. when n is divided by 28, the remainder is 3
The possible reminders can be 1,2,3,4,5 and 6. We have the pinpoint the exact remainder from this 6 numbers.
St 1: when n is divided by 21 ( 7 and 3) the remainder is an odd number.
But it cannot be 7, 3 or 9 . Hence the possibilities are : 1 and 5.
Hence there can be two remainders ,1 and 5, when divided by 7.
NOT SUFFICIENT
St 2: when n is divided by 28 the remainder is 3.
As 7 is a factor of 28, the remainder when divided by 7 will be 3
SUFFICIENT
MY QUESTION: Has anybody a rule to this statement above (bold)?
thx
