1 and 1125.
1125 is not a prime number because it has more than two factors
No. Consider:1125 = 45 * 25 = 9 * 5 * 5 * 5 = 3 * 3 * 5 * 5 * 5A prime number is defined as an integer that has no factors, so 1125 does not meet that qualification. It is instead a composite number.
1125 ends in a 5, so it is divisible by 5. Divide 1125/5 and see what you get. Then find the factors of that new smaller number. This is how you factor numbers.
1125
composite
1125 = 3 x 3 x 5 x 5 x 5
To the nearest whole number, 7
That is 1125
1125
yes
80% of 1125 = 0.80 x 1125 = 900