Question

Amina thinks of a number and subtracts 5/2 from it. She multiplies the result by 8. The
result now obtained is 3 times the same number she thought of. What is the number?​

Answer 1

AnswEr :

$\:\bullet\:\sf\ Let \: the \: no. \: be \: \bf\ y$

$\rule{100}1$

$\normalsize\quad\sf\underbrace{When \: 5/2 \: is \: subtracted}_{\large\ y - \frac{5}{2} }$

$\normalsize\quad\sf\underbrace{Multiplied \: result \: by \: 8}_{\large\ 8 \left(y - \frac{5}{2} \right)}$

$\rule{100}1$

$\underline{\dag\:\textsf{According \: to \: given \: in \: question:}}$

$\normalsize\ : \implies\sf\ 3 \times\ number = Number \: formed$

$\normalsize\ : \implies\sf\ 3y = 8 \left( y - \frac{5}{2} \right)$

$\normalsize\ : \implies\sf\ 3y = 8 \left( 2y - 10 \right)$

$\normalsize\ : \implies\sf\ 3y = 8y - 10$

$\scriptsize\sf{\: \: \: \: \: \: \: \: \: \dag\ Cancel \: negative \: signs \: both \: side}$

$\normalsize\ : \implies\sf\ -5y = - 10$

$\normalsize\ : \implies\sf\ y = \frac{\cancel{10}}{\cancel{2}}$

$\normalsize\ : \implies\sf\ y = 2$

$\therefore\:\underline{\textsf{Hence, \: the \: required\: number \: is}{\textbf{\:4}}}$

Answer 2

Answer:

★ Number was 4 ★

Step-by-step explanation:

Given:

• Amina subtracts 5/2 from a number ( say x )
• She multiplied the result by 8 after subtracting
• Final result obtained after calculation is 3 times the number ( 3x)

To Find:

• What is value of number ( x )

Solution:

A/q

→ Number was x and after subtracting 5/2 it becomes = x – $\huge{\sf {\frac{</strong><strong>5</strong><strong>}{2}}}$

→ After multiplying the result by 8( after subtraction) it became 8 ( x – $\huge{\sf {\frac{</strong><strong>5</strong><strong>}{2}}}$ )

→ The final result obtained is 3 times of x = 3x

$\small\implies{\sf }$ 3(x) = 8( x – $\huge{\sf {\frac{5}{2}}}$ )

$\small\implies{\sf }$ 3x = 8 ( $\huge{\sf {\frac{</strong><strong>2</strong><strong>x</strong><strong>-</strong><strong>5</strong><strong>}{2}}}$ )

$\small\implies{\sf }$ 3x = $\huge{\sf {\frac{</strong><strong>1</strong><strong>6</strong><strong>x</strong><strong>-</strong><strong>4</strong><strong>0</strong><strong>}{2}}}$

$\small\implies{\sf }$ 6x = 16x – 40

$\small\implies{\sf }$ 6x – 16x = –40

$\small\implies{\sf }$ – 10x = –40

$\small\implies{\sf }$ x = $\huge{\sf {\frac{</strong><strong>-</strong><strong>4</strong><strong>0</strong><strong>}{</strong><strong>-</strong><strong>1</strong><strong>0</strong><strong>}}}$ = 4

Hence, The number was x = 4