Prime number is only divisible by 1 and itself. ... No other whole numbers can multiply together to make 11. 15 is not a prime number because the factors of 15 are 1, 3, 5 and15 ( ). 15 has more than 2 factors, so it is not a prime number. true or false

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.