🔁 Successive % Change
2 exam question types, fully solvedTwo percentage changes one after another never simply add up — the second change sits on the already-changed value, not the original.
A change of a% then b% gives a net change of %. Write any decrease as a negative number.
• Up 20% then up 25%: = +50%.
• Up 10% then down 10%: = −1% (never 0%).
Special case: up x% then down x% always loses %. Since price × quantity = expenditure, a 20% price rise with 20% less bought drops the spend by 4%.
For a value compounding the SAME rate over years, multiply: final = .
Up 10% then up 10%: net = = %.
Q1A salary rises 10% then falls 10%. Net change is:
Q2A price rises 20% then 25%. The single equivalent rise is:
Q3A number falls 20% then 20% again. Net change:
Real exam questions — Successive % Change
2 question types · 6 solved examples from real SSC papersTwo changes in a row never just add up — the second sits on the new value. One formula handles them all.
Shortcut: a first change of a% followed by b% gives a net change of %. Write any decrease as a negative number.
A positive result is a net rise; a negative result is a net fall.
Special case — equal up then down by x%: the net is always a fall of %, never zero.
A number is increased by 30%, then the result is decreased by 30%. The net change is:
The price of rice rises by 20%, so a family buys 20% less of it. The change in their rice expenditure is:
The length of a rectangle is increased by 7% and its breadth by 6%. The percentage increase in its area is: