Question

if a:b=5:9 and b:c=4:7, find a:b:c and a:c ?

Explain and answer with detailed steps.

Answer 1

we know that,
a:b=5:9
b:c=4:7
so,b is common in both.
so,5:9*4=20:36
4:7*9=36:63
so,36 is common in both which is the value of b.
therefore,
a:b:c=20:36:63       and
a:c=20:63

Answer 2

Answer:

20:36:63

Step-by-step explanation:

First we find the lcm of the two b's that is 9 and 4.

Lcm of 9 and 4 = 36 = b

Now we multiply 'a' which is 5 with 'b'(in the second ratio) which is 4.

5 X 4 = 20 = a

Then we multiply 'b' ( In the first ratio) which is 9 and 'c' which is 7.

9 X 7 = 63 = c

Now if we arrange it in order we get

a = 20 : b = 36 : c = 63

= 20 : 36 : 63

Thus the answer is 20 : 36 : 63.