15 divided by 4 gives a remainder of 3, hence 15 mod 4 = 3.

To convert 10 to base-3, divide by 3: 10 ÷ 3 = 3 remainder 1, 3 ÷ 3 = 1 remainder 0, 1 ÷ 3 = 0 remainder 1. Reading the remainders from bottom to top gives 110.

In base 8, the decimal number 15 is represented as '17'.

The decimal number 15 is represented as '1111' in binary.

In hexadecimal, the decimal number 15 is represented as F.

15 in decimal is represented as '33' in base-4 (3*4^1 + 3*4^0 = 12 + 3 = 15).

25 in decimal is represented as '31' in base-8 (3*8^1 + 1*8^0 = 24 + 1 = 25).

The GCD of 48 and 180 is 12, as it is the largest number that divides both without a remainder.

The GCF of 48 and 180 is 12.

The LCM of 9 and 12 is 36, as it is the smallest number that both can divide evenly.

The least common multiple of 8 and 12 is 24, but the next multiple is 48.

The multiples of 7 are 7, 14, 21, 28, 35, 42, 49, 56, ... The smallest multiple greater than 50 is 56.

15 is the smallest common multiple of 3 and 5, and 30 is also a common multiple. However, 15 is the first one listed.

12 is the smallest common multiple of 4 and 6, and 24 is also a common multiple, but 12 is the smallest.

12 is a factor of 144 because 144 ÷ 12 = 12, which is an integer.

12 is a factor of 48, as 48 divided by 12 equals 4, which is an integer.

12 is a factor of 60 as 60 divided by 12 equals 5 with no remainder.

12 is the smallest number that is a multiple of both 4 and 6.

The LCM of 8 and 12 is 24, which is a multiple of both.

121 is divisible by 11, as 121 = 11 x 11.

A number is divisible by 15 if it is divisible by both 3 and 5. 30 meets both criteria.

28 is divisible by 7 (28 ÷ 7 = 4). The other numbers are not.

A number is divisible by 8 if the last three digits form a number that is divisible by 8. 64 is divisible by 8.

A number is divisible by both 2 and 5 if it ends in 0. 20 ends in 0, thus it is divisible by both.

7 is not a factor of 60, as 60 cannot be divided evenly by 7.

50 is not a multiple of 11, while the others are.

35 is not a multiple of 6, while 18, 24, and 30 are all multiples of 6.

To check divisibility by 11, subtract the last digit from the rest of the number. For 154, 15 - 4 = 11, which is divisible by 11. The others are divisible.

55 is not divisible by 12, as it does not meet the criteria of being divisible by both 3 and 4.

A number is divisible by 3 if the sum of its digits is divisible by 3. The sum of the digits of 22 (2 + 2 = 4) is not divisible by 3.