In the following numbers, which are common multiples of both 6 and 7? 13, 14, 24, 28, 42, 69.

What are factors of 18?

What are multiple of 15 which are less than 100?

In the following numbers, which are prime numbers? 1, 3, 2, 8, 16, 17

In early morning, the temperature in Washington was -2 degree celcius. During the day, the temperature went up 10 degree celcius. What was the temperature at midday in Washington?

Find the lowest common multiple of 6 and 9

At 9 p.m the temperature in Washington was -2 degree celcius. During the night, the temperature went down 5 degrees. So what was the temperature at midnight in Washington?

Find the lowest common multiple of 12 and 15.

Find the factors of 60 that are prime numbers

Find the common factors of 18 and 27