We have the following formula: If a number n divided by a, surplus b then (n - b) is divisible by a.
Example: 14 divide 3 by 2, and 14 - 2 = 12 divide by 3
Return to the problem Call the number to find n.
We have n - 7 divisible by 11, 13, 17, which is divisible by 11 x 13 x 17 = 2431
Since 2431 is not the 4 digit number, we increase n - 7 by 9999 9999: 2431 = 4 by 275.
Let n - 7 = 2431 x 4 = 9724.
Vâỵn = 9724 + 7 = 9731

We have the following formula: If a number n divided by a, surplus b then (n - b) is divisible by a.
Example: 14 divide 3 by 2, and 14 - 2 = 12 divide by 3
Return to the problem Call the number to find n.
We have n - 7 divisible by 11, 13, 17, which is divisible by 11 x 13 x 17 = 2431
Since 2431 is not the 4 digit number, we increase n - 7 by 9999 9999: 2431 = 4 by 275.
Let n - 7 = 2431 x 4 = 9724.
Vâỵn = 9724 + 7 = 9731