A number is first increased by 35% and then again increased by 25%. The number, so obtained, is decreased by 40%. The net increase or decrease per cent in the number is:
- Aincrease by 20%
- Bdecrease by 1.25%
- Cdecrease by 12.5%
- Dincrease by 1.25%
Solution & Step-by-step Explanation
Let the initial number be 100.
First change: Increased by 35%
New number=100×(1+
100
35
)=135
Second change: Increased by 25%
New number=135×(1+
100
25
)=135×1.25=168.75
Third change: Decreased by 40%
Final number=168.75×(1−
100
40
)=168.75×0.6=101.25
Net change:
Final Value−Initial Value=101.25−100=+1.25
Since the value is positive, it represents an increase of 1.25%.
First change: Increased by 35%
New number=100×(1+
100
35
)=135
Second change: Increased by 25%
New number=135×(1+
100
25
)=135×1.25=168.75
Third change: Decreased by 40%
Final number=168.75×(1−
100
40
)=168.75×0.6=101.25
Net change:
Final Value−Initial Value=101.25−100=+1.25
Since the value is positive, it represents an increase of 1.25%.