Question

The cost of an article is first increased by 20% and then decreased by 30%, find the percentage change in the cost of the article.

Answer 1

Let the original cost = Rs. 100
Increased by 20%
$\therefore$ New cost = 100+20 = Rs. 120
Decreased by 30% = $\frac{120\times 30}{100}$ = Rs.36
$\therefore$ New cost = 120 - 36 = Rs. 84
Overall change = 100-84 = Rs. 16
Required percentage = $\frac{16}{100}\times 100$ = 16% decrease