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What is the remainder when 1551*1553*1555*1557*1559 is divided by 10?
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25 Feb 2022, 07:50
25 Feb 2022, 07:50
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What is the remainder when 1551*1553*1555*1557*1559 is divided by 10?
(A) 0
(B) 2
(C) 5
(D) 7
(E) 9
(A) 0
(B) 2
(C) 5
(D) 7
(E) 9
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What is the remainder when 1551*1553*1555*1557*1559 is divided by 10?
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25 Feb 2022, 09:35
25 Feb 2022, 09:35
Carcass wrote:
What is the remainder when 1551*1553*1555*1557*1559 is divided by 10?
(A) 0
(B) 2
(C) 5
(D) 7
(E) 9
(A) 0
(B) 2
(C) 5
(D) 7
(E) 9
Important property: The remainder when positive integer N is divided by 10 is equal to the units digit of 10
So, the question is really asking us to find the units digit of the product (1551)(1553)(1555)(1557)(1559)
Since all five numbers in the product are ODD, the product must be ODD, which means the units digit must be odd.
So, we can eliminate choices A and B
Next, since 1555 is a multiple of 5, we know that the entire product must be a multiple of 5.
So, the units digit of (1551)(1553)(1555)(1557(1559) is either 5 or 0, which means the correct answer is C (since we've already eliminated choice A)
Re: What is the remainder when 1551*1553*1555*1557*1559 is divided by 10?
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27 Feb 2022, 12:36
27 Feb 2022, 12:36
GreenlightTestPrep Any issue with just multiplying the units digits, dividing the result by 10, and taking the remainder from there?
