A number when divided by 5 and 7 successively, leaves the remainder 2 ...
Problem: A number when divided by 5 and 7 successively, leaves the remainder 2 and 4 respectively. Find the remainder when the same number is divided by 35?
Solution:
Given, when the number is divided by 5, the remainder is 2 and when the same number is divided by 7, the remainder is 4.
We need to find the remainder when the same number is divided by 35.
Method:
To find the remainder when the number is divided by 35, we need to find the number first.
We can use the Chinese Remainder Theorem to find the number.
Step 1:
Let the number be x.
x ≡ 2 (mod 5)
x ≡ 4 (mod 7)
Step 2:
We need to find a number y such that
5 × y ≡ 1 (mod 7)
We can see that y = 3 satisfies the above equation since
5 × 3 = 15 ≡ 1 (mod 7)
Step 3:
Using the above value of y, we can find the value of x as
x = (2 × 7 × 3 – 4 × 5 × 3) mod (5 × 7)
x = (42 – 60) mod 35
x = 17
Therefore, the number is 17.
Step 4:
To find the remainder when 17 is divided by 35, we can use the following formula:
Remainder = Number – (Divisor × Quotient)
Remainder = 17 – (35 × 0)
Remainder = 17
Therefore, the remainder when the number is divided by 35 is 17.
Answer: The remainder when the number is divided by 35 is 17.
A number when divided by 5 and 7 successively, leaves the remainder 2 ...
No can be represented as 5a+2 or 7b+4
put b=0,1,2,3,4 etc and saw that for b=4 we get 32 which also fits in 5a+2 category when a=6
326 will give 32
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