factors, prime factors, Common factors and HCF

1. Find the common factor of 15, 30 and 45.

• 1,3,15 and 30

• 1,3,5 and 15

• 1,2,3,4,5,15 and 30

Express 90 as a product of prime numbers.

• 2x3x3x5

• 2x2x3x3x5

• 2x3x5

write 6400 in index form.

• 6.4X10^2

• 6.4X10^3

• 6.4X10^4

Write 250 as a product of prime numbers.

• 2X2X5X5X5

• 2X5X5

• 2X5X5X5

Find the prime factors of 256

• 2

• 2 and 3

• 2,3 and 5