Integer

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Integer

by Veronica » Sun Sep 26, 2010 8:26 pm
What is the remainder when the positive integer n is divided by 3?
1. The remainder when n is divided by 2 is 1
2. The remainder when n + 1 is divided by 3 is 2

Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?
1. She bought $4.4 worth of stamps
2. She bought an equal number of $0.15 stamps and $0.29 stamps

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by debmalya_dutta » Sun Sep 26, 2010 8:38 pm
Veronica wrote:What is the remainder when the positive integer n is divided by 3?
1. The remainder when n is divided by 2 is 1
2. The remainder when n + 1 is divided by 3 is 2

Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?
1. She bought $4.4 worth of stamps
2. She bought an equal number of $0.15 stamps and $0.29 stamps
Is it B and A?
@Deb

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by Veronica » Sun Sep 26, 2010 11:21 pm
debmalya_dutta wrote:
Veronica wrote:What is the remainder when the positive integer n is divided by 3?
1. The remainder when n is divided by 2 is 1
2. The remainder when n + 1 is divided by 3 is 2

Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?
1. She bought $4.4 worth of stamps
2. She bought an equal number of $0.15 stamps and $0.29 stamps
Is it B and A?


Yes, please explain in detail, thank you!

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by hi.itz.mani » Sun Sep 26, 2010 11:38 pm
What is the remainder when the positive integer n is divided by 3?
1. The remainder when n is divided by 2 is 1
2. The remainder when n + 1 is divided by 3 is 2

Statement 1 is insufficient . Example 5 when divided by 2 , remainder is 1 and when divided by 3, remainder is 2
9 when divided by 2 , remaider is 1 but when divided by 3 remainder is 0


Statement 2 is sufficient . if n + 1 where n is positive integer leaves remainder 2 when divided by 3 then surely remainder will be 1 when n is divided by 3.

Hence answer is B

Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?
1. She bought $4.4 worth of stamps
2. She bought an equal number of $0.15 stamps and $0.29 stamps

From statement 1
15 x + 29 y = 440
here x and y have to be positive whole numbers.
x = (440 - 29 y ) / 15
now for x to be positive whole number 440 - 29 y = 15 K
this is only possible when 440 - 29 Y results in 0 or 5 in unit place . For this Y needs to be a multiple of 5
when y = 5 x = not a whole number
when y = 10 x = 10
when y = 15 x = 5 / 15
when y = 20 x = -ve

Hence from statement 1 we get x = 10 and Y = 10 .

Statement 2. not suffiecient .

Hence Answer is A