Clerkship Arithmetic Quiz: Percentage (12 Questions)

$\frac{45}{60} \times 100 = \frac{3}{4} \times 100 = 75\%$. Divide by the number that follows "of" (60). 80% would need $\frac{48}{60}$.

$\frac{1}{8} = 12.5\%$, so $\frac{3}{8} = 3 \times 12.5 = 37.5\%$. Directly: $\frac{3}{8} \times 100 = 37.5$. 40% is $\frac{2}{5}$, close but different.

If the number is $N$, then $N \times \frac{125}{100} = 150$, so $N = 150 \times \frac{100}{125} = 120$. Check: 25% of 120 is 30 and $120 + 30 = 150$. Subtracting 25% of 150 is wrong because the percentage is on the original.

Discount = 15% of 800 = 120 (10% = 80, 5% = 40). Selling price = 800 − 120 = 680, or directly $800 \times \frac{85}{100} = 680$. ₹700 would be a 12.5% discount and ₹640 a 20% discount.

The fall is $500 - 425 = 75$. Percent fall = $\frac{75}{500} \times 100 = 15\%$. Dividing by 425 gives about 17.6%, which is wrong: always divide by the original value.

Take the price as 100: after 20% it is 80, then 10% of 80 = 8 gives 72. Total discount = 28%. By formula $20 + 10 - \frac{20 \times 10}{100} = 28$. It would be 30% only if both discounts were on the same original price.

Take B = 100, so A = 125. B is less than A by $125 - 100 = 25$, and the comparison is with A: $\frac{25}{125} \times 100 = 20\%$. It is not 25% because the base is now A (125), not B (100).

Pass marks = $140 + 20 = 160$. This is 40% of the maximum, so maximum = $\frac{160}{40} \times 100 = 400$. Check: 40% of 400 = 160. 40% of 350 is 140, which is the score, not the pass mark.

Savings = $100 - 64 = 36\%$. 36% of 25,000 = $250 \times 36 = 9000$. Check: spending is 16,000 and $25000 - 16000 = 9000$. ₹10,000 would be 40% savings.

Year 1: $20000 \times 1.1 = 22000$. Year 2: $22000 \times 1.1 = 24200$. 24,000 comes from adding 2,000 twice, but in year 2 the base is 22,000.

Take the side as 10, so the area is 100. The side becomes 11 and the area 121. The increase is 21, so 21%. By formula $10 + 10 + \frac{10 \times 10}{100} = 21$. The area grows in both directions, so it is 21%, not 20%.