The average 15

The average age of a group of four men whose ages are in the ratio of 2:3:4:5 is 42 years, what is the age of the eldest person of this group?

Final Answer:

d =  60

Step-by-step explanation:

$$\begin{gathered} a:b:c:d=2:3:4:5 \\ 5>4>3>2=>d>c>b>a \\ m=42 \\ a=2x \\ b=3x \\ c=4x \\ d=5x \\ m=\frac{a+b+c+d}{4}=\frac{2x+3x+4x+5x}{4} \\ 4m=14x \\ x=\frac{4}{14}\cdot m=\frac{4}{14}\cdot 42=\frac{4\cdot 42}{14}=\frac{168}{14}=12 \\ d=5\cdot x=5\cdot 12=60 \end{gathered}$$

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