Question

where did he get the 80 from?​

Answer 1

Step-by-step explanation:

see in the attachment above

if u still hv doubt then comment below

Answer 2

Question:

The result of a number when decreased by 20% is 192. Find the Number

⠀

Answer:

Let the required Number be n

⠀

$\underline{\bigstar\:\textsf{According to the given Question :}}$

$:\implies\sf Result=Number - (Number \times 20\%)\\\\\\:\implies\sf 192 =n - \bigg(n \times \dfrac{20}{100}\bigg)\\\\\\:\implies\sf 192 =n - \dfrac{20n}{100}\\\\\\:\implies\sf 192 = \dfrac{(n \times 100) - 20n}{100}\\\\\\:\implies\sf 192 = \dfrac{100n - 20n}{100}\\\\\\:\implies\sf 192 = \dfrac{80n}{100}\\\\\\:\implies\sf 192 \times \dfrac{100}{80} = n\\\\\\:\implies\sf 192 \times \dfrac{10}{8} = n\\\\\\:\implies\sf 24 \times 10 = n\\\\\\:\implies\sf n = 240$

⠀

$\therefore\:\underline{\textsf{Hence, the required number is \textbf{240}}}.$