Percentage Questions for SSC MTS

What is Percentage?

Percentage simply means 'per hundred'. When we say 40%, we mean 40 out of every 100. Think of it like slicing a roti into 100 equal pieces — 40% means you took 40 pieces. To convert a fraction or decimal to percent, multiply by 100. To convert percent back to a decimal, divide by 100.

• Percent means per 100. Symbol is %.
• To convert fraction to %: multiply by 100. Example: 3/4 = 75%.
• To convert % to fraction: divide by 100. Example: 25% = 25/100 = 1/4.
• To convert % to decimal: divide by 100. Example: 35% = 0.35.
• Memorise common fraction-percent pairs to save time.

Key Fraction-Percent Table (Memorise These)

SSC MTS questions often involve standard fractions. If you remember these by heart, you avoid long division during the exam and solve in seconds. This is one of the biggest time-savers at MTS level.

• 1/2 = 50%, 1/3 = 33.33%, 1/4 = 25%, 1/5 = 20%
• 1/6 = 16.67%, 1/7 = 14.28%, 1/8 = 12.5%, 1/10 = 10%
• 2/3 = 66.67%, 3/4 = 75%, 2/5 = 40%, 3/5 = 60%
• 1/9 = 11.11%, 1/11 = 9.09%, 1/12 = 8.33%
• Reverse: 25% means 1/4 of the value. Use this for quick mental math.

Percentage Increase and Decrease

This is the most tested sub-type in MTS. You are given an old value and a new value and asked how much percent it went up or down, or vice versa. Always remember: the denominator in the % change formula is the ORIGINAL (old) value, never the new one. Many students accidentally use the new value and lose marks.

• % Increase = (Increase / Original) x 100.
• % Decrease = (Decrease / Original) x 100.
• If price rises by 20%, to bring it back to original, reduce by 16.67% (not 20%).
• If a value increases by R%, the reverse decrease = R/(100+R) x 100 percent.
• If a value decreases by R%, the reverse increase = R/(100-R) x 100 percent.

Successive Percentage Change

Sometimes a value changes by two percentages one after the other. For example, a salary first increases by 10% then decreases by 10%. Many people think it comes back to the original — it does NOT. There is always a net loss in such cases. Use the net effect formula to find the combined result directly without calculating step by step.

• Two successive changes of A% and B% give net effect of: A + B + (AB/100) %.
• If both are increases, result is positive (net gain).
• If one is increase and one is decrease, put a minus sign on the decrease value.
• If both are decreases, both A and B are negative.
• 10% up then 10% down = net change of 10 + (-10) + (10 x -10)/100 = -1% (net loss of 1%).

• Using the NEW value instead of the OLD value in the denominator of % change formula. Always divide by original.
• Thinking 10% increase followed by 10% decrease brings you back to the same number. It does not — you lose 1%.
• Confusing 'A is what % of B' with 'A is what % more than B'. These are completely different questions.
• Forgetting to put a negative sign for decrease in the successive change formula, which flips the answer.
• Not memorising the fraction-percent table and wasting 30-40 seconds doing manual division for 1/3, 2/3, etc.

• OPOD Rule: Old value goes On the bottom Of Division. % change = change divided by OLD value.
• 10-10 Trap: 10 up, 10 down = minus 1 percent. Same % up and down always gives a NET LOSS. Remember: Up-Down = Frown (loss).
• For successive changes, remember the formula A + B + AB/100 as ADD BOTH then ADD their PRODUCT over 100.
• Fraction table trick: To get % of 1/n, just divide 100 by n. Example: 1/8 means 100 divided by 8 = 12.5%.

• SSC MTS typically asks one direct % of a number question and one % increase/decrease question. Both are solvable in under 60 seconds if fraction table is memorised.
• Successive percentage questions appear occasionally. They look scary but the A+B+AB/100 formula solves them in 20 seconds.
• Watch out for questions that say 'by what percent is A more than B' vs 'by what percent is A less than B' — denominator changes.
• At MTS level, answers are mostly clean whole numbers or simple decimals like 12.5 or 33.33. If you are getting a messy number, re-check which value you used as denominator.
• Percentage questions in MTS rarely exceed two steps. If your solution is getting long, you are overcomplicating it — look for a shortcut or fraction equivalent.