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If a:b=3:4 and b:c=4:1, then a:b:c=?
1 : 3
3 : 1
4 : 1
1 : 4
4 : 1
Since the common term 'b' has the same value (4) in both ratios (a:b=3:4 and b:c=4:1), you can directly combine them as 3:4:1.
a : b = 3 : 4 and b : c = 4 : 1
a:b:c=(a├Чb1тАЛ):(b├Чb1тАЛ):(c├Чb2тАЛ)
Since the common term 'b' has the same value (4) in both ratios (a:b=3:4 and b:c=4:1), you can directly combine them as 3:4:1.
Students often mistakenly multiply all terms or cross-multiply without aligning the common ratio term 'b.
Step 1: Write down the given ratios
We are given two individual ratios: a:b=3:4 and b:c=4:1.
a:b=3:4,b:c=4:1
Step 2: Check the common term
The common term in both ratios is b. In the first ratio, b=4, and in the second ratio, b=4.
b=4┬а(common┬аin┬аboth)
Step 3: Combine the ratios
Since the value of the common term b is identical in both ratios, we can directly write the combined ratio a:b:c as 3:4:1.
a:b:c=3:4:1
C is correct because combining the given ratios a:b=3:4 and b:c=4:1 directly yields 3:4:1 since the common term b is already equal to 4.
This fundamental ratio-combining technique is widely used in partnership, mixture, and alligation problems in quantitative aptitude.