This is an important and very basic ques from the Book ML Aggarwal class 10th,, chapter – 7, ratio and proportion.

In this ques we have a:b, b:c and we have to find a:b:c

And in the second part we have 3a=4b=6c amd we have to find a:b:c

Question 10, ML Aggarwal

Solution:(i) We know that

A: B = 1/4 × 5/1 = 5/4

B: C = 1/7 × 6/1 = 6/7

Here the LCM of B terms 4 and 6 is 12

Now making terms of B as 12

A/B = (5 × 3)/ (4 × 3) = 15/12 = 15: 12

B/C = (6 × 2)/ (7 × 2) = 12/14 = 12: 14

So A: B: C = 15: 12: 14

(ii) It is given that

3A = 4B

We can write it as

A/B = 4/3

A: B = 4: 3

Similarly 4B = 6C

We can write it as

B/C = 6/4 = 3/2

B: C = 3: 2

So we get

A: B: C = 4: 3: 2