Question

What number when increased by 15% becomes 230?

Answer 1

Let the number be = 100

Increase = 15% = 15

∴ Increased number = 100 + 15 = 115

If increased number is 115, then original number is 100.

and if increased number is 230, then original number ${\displaystyle =\frac{100}{115}\times 230=200}$

Answer 2

Let the number be x

∴ 15% of x

∴ value = ${\displaystyle \frac{\text{percent}}{100}\times \text{total}}$

${\displaystyle =\frac{15}{100}\times x}$

∴ value of 15% = ${\displaystyle \frac{3x}{20}}$

${\displaystyle \Rightarrow x+\frac{3x}{20}=230}$

${\displaystyle \Rightarrow \frac{x}{1}+\frac{3x}{20}=230}$

LCM of 1 & 20 is 20

${\displaystyle \Rightarrow \frac{x}{1}+\frac{3x}{20}=230}$

${\displaystyle \Rightarrow \frac{20x}{20}+\frac{3x}{20}=230}$

${\displaystyle \Rightarrow \frac{23x}{20}=230}$

⇒ 23x = 230 × 20

⇒  23x = 4600

⇒ x = ${\displaystyle \frac{4600}{23}}$

⇒ x = 200