Question

divisibility rule for 14,15,16,18,36​

Answer 1

14 It is divisible by 2 and by 7.

Add the last two digits to twice the rest. The result must be divisible by 14.

15 It is divisible by 3 and by 5.

A number is divisible by 16 if the thousands digit is even and the last three digits form a number that is divisible by 16. A number is also divisible by 16 if the thousands digit is odd and the number formed by the last three digits plus 8 is divisible by 16.

Thus we must check for divisibility by 4 and 9 to see if it's divisible by 36. Since the last two digits, 44, of the number is divisible by 4, so is the entire number. To check for divisibility by 9, we look to see if the sum of the digits is divisible by 9.

Answer 2

Step-by-step explanation:

Add the last two digits to twice the rest. The result must be divisible by 14.

ex: 364 =3×2 +64 = 6 + 64 = 70

It is divisible by 3 and by 5

ex: 390 is divisible by 3 &5.

so 390 is divisible by 15.

Add the last two digits to four times the rest. The result must be divisible by 16.

ex: 1168 = 11×4 + 68 = 44 + 68 = 112

It is divisible by 2 and by 9.

ex: 342 is divisible by 2 &9.

so 342 is divisible by 18.