Ex.4.4 Q4 Simple-Equations Solution - NCERT Maths Class 7

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Question

Solve the following riddle:

I am a number,                       Tell my identity!

Take me seven times over     And add a fifty!

To reach a triple century         You still need forty!

Text Solution

What is Known?

A riddle.

What is unknown?

The number in the riddle.

Reasoning:

Use the given information to make an equation with unknown number as a variable. Solve the equation to get value of the number.

Steps:

Let the number be\( x\).

According to question,

\[\begin{align}7x + 50 + 40 &= 300\\7x &= 300 - 90\\7x &= 210\\x = \frac{{210}}{7}&= 30\end{align}\]

Therefore, the number is \(30\)

  
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