Posts Tagged ‘Divisibility’

A number is divisible by ........By 7, 11, and 13 if it consists of but four places, the first and fourth being occupied by the same significant figures, and the second and third by ciphers.” (A cipher is a 0.) It continues: “Thus, 2002, 3003, and 5005 are divisible by 7, 11, and 13.” Proof:  ... Full story

A whole number, N, is a multiple of 7 if the following procedure leads to another multiple of 7*: (1) Subtract the ones digit from N, (2) Dividing the result by 10, and (3) Subtract—from that result—twice the original ones digit. *the multiple of 7 may be 0 or negative. This is best explained in an example. Consider 7 x ... Full story

Though Remainders are never negative but somtime some questions of finding the remainder become easy by using Negative Remainders. First of all, What is Negative Remainder: eg. When 14 is divided by 8 Then, 14= 8x1+6 or 14=8x2-2 Therefore, We have two remainder and they are +6 and -2 where (-2) is the Negative Remainder. I hope I am able to make it ... Full story

While checking the divisibilty test for number 7 I came across a new thing and i.e Any six-digit, or twelve-digit, or eighteen-digit, or any such number with number of digits equal to multiple of 6, is divisible by EACH of 7, 11 and 13 if all of its digits are same . For example 666666, 888888888888 etc. are all divisible by 7, 11, and 13. Full story