U123

(a)

(i) A Factor Tree for 2475 as a product of prime factors:

2475

/       \

825      3

/           \

275          3

/     \

55     5

/      \

11     5

So the prime factorisation for 2475 is: 3 x 5 x 11 = 3 x 3 x 5 x 5 x 11 = 2475

(ii) As a fraction in its simplest form: To find the greatest common factor for each fraction

equals :

3 x 18 = 54

4 x 18 = 72

equals:

4 x 11 = 44

4 x 18=  72

(iii) A simplified surd:

= 2 x 3

(b)

(i) The ratio of students that did attend the test compared to those who were absent

252 / 28 = 9

So the ratio would be 9:1

Meaning for every absent student that did not take the test, nine students did….(short extract)