LCM/HCF using Product of Primes Textbook Answers

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Workout

Question 1:

(a)  105

(b)  154

(c)  105

(d)  99

(e)  60

(f)   90

(g)  80

(h)  120

(i)   144

(j)   78

(k)  150

(l)   144

(m)  168

(n)   180

(o)  360

(p)  630

Question 2:

(a)  7

(b) 5

(c)  6

(d)  9

(e)  15

(f)   14

(g)  30

(h)  16

(i)   8

(j)   1

(k)  12

(l)   19

(m) 11

(n)  28

(o)  45

(p)  32

Apply

Question 1(a)  420

1(b)  12

Question 2:  300

Question 3:  168 seconds

Question 4:  1pm or 13:00

Question 5:  6200

Question 6:  26 and 65

Question 7:  The highest common factor of 20 and 21 is 1.

Question 8: 1200 coins each, so they have 2400 in total.

Question 9: It should be 4, since 2 x 2 = 4. Perhaps he just put the two 2’s beside each other to make 22 instead of multiplying them.