Question

if A:B=5:8. and B:C= 18:25, then find A:B:C​

Answer 1

Given,

A/B=5/8,. B/C=18/25

A/B=5/8 ×18 = 90/144 ( We get 90/144 by dividing both numerator and denominator by 18)

B/C=18/25 × 8= 144/200 ( By dividing both numerator and denominator by 8)

Now,

A/B/C = 90/144/200

= 45/72/100

Answer 2

Given that a:b=5:8 and b:c=18:25

Here the common term is b which is found in both the ratios.

ok, now let’s look at the value of b in 1st ratio. It is 8. And 18 in the second.

Now we have to take the LCM of these two values so that we are changing the value of b into the LCM value in both the ratios. The LCM is 72.

So we change the value of b into 72 in the 1st and 2nd ratio. 8*9=72. So multiply the whole 1st ratio by 9 making a:b=45:40

Similarly change the value of b as 72 in the second ratio. 18*4=36. Hence multiply the entire second ratio by 4 making b:c=72:100

Now that the value of b in both the ratio being same we can concatenate them. Hence a:b:c=45:72:100