Question

Gujarati

Hindi

4.Average

hard

Eleven years earlier the average age of a family of $4$ members was $28 \,years.$ Now the age of the same family with six members js yet the same, even when $2$ children were born in this period. If they belong to the same parents and the age of the first child at the time of the birth of the younger child was same as there were total family members just after the birth of the youngest member of this family, then the present age of the youngest member of the family is in $year$?

Solution

$\begin{array}{|c|c|c|c|} \hline & \begin{array}{c} \text { No. of family } \\ \text { member } \end{array} & \text { Average } & \text { Total } \\ \hline \begin{array}{c} \text { Eleven years } \\ \text { Earlier } \end{array} & 4 & 28 & 112 \\ \hline \text { Presently } & \text { if } 4 & 39 & 156 \\ \hline & 6 & 28 & 168 \\ \hline \end{array}$

Since it is obvious that the youngest member (i.e. child) was the $6^{\text {th }}$ family member in the family. Therefore at the time of the birth of the youngest child the elder child's age was $6 \,years.$

Now the sum of their ages

Let age of the youngest member $=x$

$x+x+6=(168-156) \Rightarrow 2 x+6=12 \Rightarrow x=3$

Then the present age of the youngest member of the familly is $=3$ $years.$

Std 13

Quantitative Aptitude

The arithmetie mean of the scores of a group of students in a test was $52 .$ The brightest $20 \%$ of them secured a mean score of $80$ and the dullest $25 \%$ a mean score of $31.$ The mean score of remaining $55 \%$ is

medium

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medium

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medium

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medium

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medium

Solution

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