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Answer 1 · 2017-01-01T16:12:27

$13440

Let her monthly income = $x.

she saves = x of $\frac{2}{7} = \frac{2}{7} \cdot x$ $2/7 = 2/ 7 * x$

So she spends = $x - \frac{2}{7} x = \frac{7 x - 2 x}{7} = \frac{5 x}{7}$ $x - 2/7 x = [7x -2x]/7 = [5x]/7$

Now as per question,

$\frac{5 x}{7} = 800$ $[5x]/7 = 800$

$\Rightarrow x = \frac{800 \cdot 7}{5} = 1120$ $rArr x = [800 * 7]/5 = 1120$

Hence her monthly income is $1120

her yearly income will be $1120 * 12 = $13440

Answer 2 · 2017-01-01T16:36:18

$$ 13, 440$ $$13,440$

Nityananda has shown an algebraic solution, by forming and solving an equation.

You can also do this using direct proportion.

If the lady saves $\frac{2}{7}$ $2/7$ of her income, it means she spends $\frac{5}{7}$ $5/7$

You are told that the amount she spends is $800.

So, if $800 represents $\frac{5}{7}$ $5/7$ , how much will represent $\frac{7}{7}$ $7/7$ ?

$800:5 = square:7$ This can be written as:

$800/5 =square/7$

The relationship between $5 and 800$ will be the same as between $7 and square$

$800 div 5= 160$

$:. square = 7 xx160 = 1120$

This is her monthly income.

Her annual income will be $1120 xx12 = $13,440$