Question

The price of a book was raised by x%. Then it was slashed by 20% to bring it to the
earlier level. Find the value of x.​

Answer 1

||✪✪ QUESTION ✪✪||

The price of a book was raised by x%. Then it was slashed by 20% to bring it to the earlier level. Find the value of x.?

|| ✰✰ ANSWER ✰✰ ||

Lets Assume That, original Price of book was Rs.100.

Now , It was Raised by x% .

So,

→ New price = [100*(100+x)/100] = Rs. (100+x).

Now , Given That, when we Slashed New price by 20% we get our original price .

So,

→ [(100+x)*80]/100 = 100

→ (100+x)*80 = 100*100

→ 8000 + 80x = 10000

→ 80x = 10000-8000

→ 80x = 2000

→ x = (2000/80)

→ x = 25% . (Ans).

Hence, Value of X was 25%.

Answer 2

Answer:

$\large{\underline{\boxed{\mathfrak\blue{Value \: of \: x = 25 }}}}$

$\rule{100}{2}$

Let the original price be Rs.M

At first,raised by x%

$\therefore$ New price = M + M × x%

→ New price = M + Mx/100

→ New price = 100M + Mx/100

A/Q,

$→ \sf \dfrac{(100M + Mx)}{100} - \dfrac{M(100 + x)}{100} \times 20\% = M \\\\ → \sf \dfrac{100M + Mx}{100} - \dfrac{M(100 + x)}{500} = M \\\\ → \sf \dfrac{5(100M + Mx) - M(100 + x)}{500} = M \\\\ → \sf 500M + 5Mx - 100M - Mx = 500M \\\\ → \sf 400M + 4Mx = 500Mx \\\\ → \sf 4Mx = 500M - 400M \\\\ → \sf 4Mx = 100M \\\\ → \sf x = \dfrac{100M}{4M} \\\\ → \large{\underline{\boxed{\sf\blue{x = 25 }}}}$

$\therefore{\underline{\text{Value \: of \: x = 25 }}}$