Question

Amina thinks of a number and subtract 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

1. let the no. is x.
2. x-5/2
3. (x-5/2)8
4. (x-5/2)8=3x
5. 8x-20=3x
6. 5x=20
7. x=4

No. is 4 ans

Answer 2

Answer

$\small\sf{\bullet{\red{Here}}}$

$\small\sf{\bullet{\blue{Given:-}}}$

• Amina thinks of a number and subtract 5/2 from it, she multiplies the results by 8.

• The result now obtained is 3 times the same number.

$\small\sf{\bullet{\green{To \: Find:-}}}$

• What is the number Amina thinks.

$\small\sf{\bullet{\pink{Solution:-}}}$

• Let, the number Amina thought be x

$\longmapsto She \: subtract \: 5/2 \: from \: it,</p><p>$

$\implies \sf x - \dfrac{5}{2}$

$\longmapsto \: She \: again \: multiples \\ the \: result \: by \: 8,$

$\implies \sf 8\bigg(x - \dfrac{5}{2}\bigg)$

Now, according to the question,

$\implies \sf 8\bigg(x - \dfrac{5}{2}\bigg)$

$\implies \sf 8x - {\cancel{8}} \times \dfrac{5}{\cancel{2}}$

$\implies \sf 8x - 4 \times 5 =\: 3x$

$\implies \sf 8x - 20 =\: 3x$

$\implies \sf 8x - 3x =\: 20$

$\implies \sf 5x =\: 20$

$\implies \sf x =\: \dfrac{\cancel{20}}{\cancel{5}}$

$\implies \sf\bold{\red{x =\: 4}}$

\therefore∴ The number that Amina thought is 4