A number is increased by 40% and then the increased number is decreased by 40%. Find the net increase or decrease percent.
Answer:
16%
- Let the number be x.
We are given that a number is increased by 40%.
So, increased percentage = (100+40)% = 140%
Then, Increased number = 140% of x=(140100×x)=75x Now, the number is decreased by 40%. So, the decreased number will be (100−40)% = 60% of the increased number. Decreased number = 60% of 75x=(60100×75x)=420500x∴ - Therefore, \begin{aligned} \text{ Net decrease }\% =& \dfrac { \text{ Net decrease } } { \text{ Original number } } \times 100\% \\ =& \bigg( \dfrac { 80 x } { 500 } \div { x } \times 100 \bigg)\% \\ = & \bigg( \dfrac { 80 x } { 500 } \times \dfrac { 1 } { x } \times 100 \bigg)\% = 16\% \end{aligned} Hence, the net decrease is 16\%.