Question

3
If a:b = 2:5 and b:c = 3:4, find (i) a:c (II) a:b:c
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Answer 1

(i) 3:10

(ii) 6:15:20

Explanation:

a : b

2 : 5

b : c

3 : 4

Since both values of b in the two ratios are different, we need to multiply each ratio so that they are the same. I will multiply the first ratio by 3 and the second ratio by 5 so that b = 15 units.

a : b

6 : 15

b : c

15 : 20

Now that both values of b are the same, we can arrange the variables a, b and c together.

Thus:

a : b : c

6 : 15 : 20

a : c

6 : 20

3 : 10