# Question fe806

Jan 1, 2017

$13440 #### Explanation: Let her monthly income =$x.

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

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

Now as per question,

$\frac{5 x}{7} = 800$

$\Rightarrow x = \frac{800 \cdot 7}{5} = 1120$

#### Explanation:

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

You can also do this using direct proportion.

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

You are told that the amount she spends is $800. So, if$800 represents $\frac{5}{7}$, how much will represent $\frac{7}{7}$?

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

$\frac{800}{5} = \frac{\square}{7}$

The relationship between $5 \mathmr{and} 800$ will be the same as between $7 \mathmr{and} \square$

$800 \div 5 = 160$

$\therefore \square = 7 \times 160 = 1120$

This is her monthly income.

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