When a number is divided by 527 gives the remainder as 21. When the sa...
Let the number be 527a + 21
when divided by 17, 527a is divisible by 17 and leaves remainder as 4 when 21 is divided by 17
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When a number is divided by 527 gives the remainder as 21. When the sa...
527 os divisible by 17 hence no remainder
when 21 is devided by 17
remainder is 4
When a number is divided by 527 gives the remainder as 21. When the sa...
Solution:
Let the number be x.
When x is divided by 527, the remainder is 21.
So, x = 527k + 21, where k is a positive integer.
We need to find the remainder when x is divided by 17.
Let's try to express x in terms of 17.
527 can be written as 17 x 31.
So, x = (17 x 31 x k) + 21
We can write (17 x 31 x k) as 527k - 10k.
So, x = 527k - 10k + 21
Now, we can see that x leaves a remainder of 21 when divided by 17 if and only if 10k leaves a remainder of 4 when divided by 17.
Let's try to find such a value of k.
10k leaves a remainder of 4 when divided by 17 means: 10k = 17n + 4, where n is a positive integer.
Solving for k, we get:
k = (17n + 4)/10
We can see that k is an integer only when n leaves a remainder of 8 when divided by 10.
Let n = 10m + 8, where m is a positive integer.
Substituting in the above equation, we get:
k = (17 x (10m + 8) + 4)/10
Simplifying, we get:
k = 17m + 14
So, for any positive integer m, k leaves a remainder of 14 when divided by 17.
Substituting in the equation for x, we get:
x = 527k - 10k + 21
x = (527 - 10)k + 21
x = 517k + 21
x leaves a remainder of 4 when divided by 17.
Therefore, the correct answer is option C (4).