Find the whole quantity if
$(a).\ 5$ % of it is $600$.
$(b).\ 12$ % of it is $Rs.\ 1080$.
$(c).\ 40$ % of it is $500\ km$.
$(d).\ 70$ % of it is $14$ minutes.
$(e).\ 8$ % of it is $40\ litres$.

AcademicMathematicsNCERTClass 7

To do: To fiind the whole quantity if:

$(a).\ 5$ % of it is $600$. 

$(b).\ 12$ % of it is $Rs.\ 1080$.

$(c).\ 40$ % of it is $500\ km$.

$(d).\ 70$ % of it is $14$ minutes. 

$(e).\ 8$ % of it is $40\ litres$.


Solution:


$(a)$. Let us assume the whole quantity be $x$,

Then,

$(\frac{5}{100})\times (x)=600$

$x=600\times (\frac{100}{5})$

$x=\frac{60000}{5}$

$x=12000$


$(b)$. Let us assume the whole quantity be $x$,

Then,

$(\frac{12}{100})\times (x)=1080$

$x=1080\times (\frac{100}{12})$

$x=540\times (\frac{100}{6})$

$x=90\times 100$

$x=Rs.\ 9000$


$(c)$. Let us assume the whole quantity be $x$,

Then,

$(\frac{40}{100})\times (x)=500$

$x=500\times (\frac{100}{40})$

$x=500\times (\frac{10}{4})$

$x=500\times 2.5$

$x=1250\ km$


$(d).\ 70$ % of $x=14\ minutes$

$\Rightarrow\ \frac{70}{100}\times x=14$

$\Rightarrow\ x=\frac{14\times100}{70}=20$
$=20\ minutes$


$(e).\ 8$ % of $x=40\ liters$ 

$\Rightarrow\ \frac{8}{100}\times x=40$

$\Rightarrow\ x=\frac{40\times100}{8}=500$
$=500\ liters$
raja
Updated on 10-Oct-2022 13:35:14

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