In a school outing with only adults and young children, the average we

Question

In a school outing with only adults and young children, the average weight of the adults is 60 kg and the average weight of the children is 24 kg. If the average weight of everyone on the school outing is 30 kg, what is the ratio of adults to children on this outing?

A) \(\frac{1}{12}\)

B) \(\frac{1}{6}\)

C) \(\frac{1}{5}\)

D) \(\frac{1}{4}\)

E) \(\frac{1}{3}\)

A)  \frac{1}{12}

B)  \frac{1}{6}

C)  \frac{1}{5}

D)  \frac{1}{4}

E)  \frac{1}{3}

yashikaaggarwal · Answer

In a school outing with only adults and young children, 
Let total no. of adult be X 
and total no. of children be Y

the average weight of the adults is 60 kg 
Total weight of adults = 60X

and the average weight of the children is 24 kg. 
Total weight of children = 24Y

If the average weight of everyone on the school outing is 30 kg,
(60X+24Y)/(X+Y) = 30
(60X+24Y) = 30X + 30Y
30X = 6Y
5X = Y
X/Y = 1/5

Adults:Children ratio = 1:5

Answer is C

IanStewart · Answer

Using alligation, if we draw the three averages on a number line:

--24----30--------------------60--

we clearly have more children, because 30 is closer to 24 than to 60. The ratio of the distances to the middle average will equal the ratio of the sizes of the groups, so the groups are in a 6 to 30 ratio, or 1 to 5 ratio. Since we have more children, the ratio of adults to children is 1 to 5.

Archit3110 · Answer

let total adults be a & children be c
so total weight of adults ; 60a and that of children ; 24c
combined weigth avg of class 
60a+24c = 30*(a+c)
6 is common so divide both sides
10a + 4c = 5 a +5c
5a =c
a/c = 1/5
OPTION C

EgmatQuantExpert · Answer

Solution

Given

• The average weight of the adults is 60 kg and the average weight of the children is 24 kg.
• The average weight of everyone on the school outing is 30 kg.

To Find

• The ratio of adults to children on this outing.

Approach and Working Out

Method 1:

• Let the number of adults be ‘a’ and the number of children be ‘b’.
 o The sum of the ages of the adults = 60a
o The sum of the ages of the children = 24b 
• Total number of individuals = a + b
 o The sum of ages of all the individuals = 30 (a + b). 
• We can say, 
 o 60a + 24b = 30 (a + b)
o 30a = 6b
o a/b = 6/30
o a/b = 1/5

Method 2: 
 • We can also apply alligation here as shown in the attachement.

Correct Answer: Option C

In a school outing with only adults and young children, the average we

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In a school outing with only adults and young children, the average we

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