Home › Certifications › 6th Math: Ratios & Proportional Relationships › Percent as a Ratio per Hundred
34 multiple-choice questions and 2 flashcards on Percent as a Ratio per Hundred, about 23% of the 6th Math: Ratios & Proportional Relationships bank. Every one carries a written rationale.
Percent as a Ratio per Hundred is one of 5 chapters in CoStudy's 6th Math: Ratios & Proportional Relationships bank, and it holds 34 of the bank's 150 multiple-choice questions — roughly 23% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.
Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.
10 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.
Convert 1.4 to a percent:
Answer: C — 140%
C) 1.4 × 100 = 140%. Percents > 100% are valid. A), B), D) Misplace the decimal.
What is 25% of 80?
Answer: A — 20
0.25 × 80 = 20. (B) confuses percent value; (C), (D) misapply.
A $50 item has a 6% sales tax. The final price is:
Answer: A — $53
Tax = 6% × 50 = $3. Total = $50 + $3 = $53. (B), (D) misapply.
What percent of 50 is 12?
Answer: A — 24%
12 ÷ 50 = 0.24 = 24%. (B), (C), (D) are common errors.
A class of 25 students has 15 who walk to school. What percent walk?
Answer: D — 60%
D) 15 ÷ 25 = 0.6 = 60%. A) Used the count as the percent. B) Used the non-walkers (10/25). C) Picked 3/4 by intuition.
45% expressed as a ratio of part to whole is:
Answer: A — 45:100
A) 45 per 100. B) Direction reversal. C) Part-to-the-rest, not part-to-whole. D) Treats 100 as 1.
After a 20% discount, an item costs $48. The original price was:
Answer: D — $60
D) $48 is 80% of original; 48 ÷ 0.80 = $60. A) Computed 20% of 48. B) Added 20% to 48 (wrong base). C) Added $20.
A meal costs $32 and you leave a 15% tip. The tip amount is:
Answer: B — $4.80
B) 0.15 × 32 = $4.80. A) Used 10% instead. C) Rough estimate. D) Used the percent as a dollar amount.
Which decimal equals 12.5%?
Answer: B — 0.125
B) 12.5 ÷ 100 = 0.125. A), C), D) Misplace the decimal.
What is 25% of 80?
Answer: C — 20
C) 25% = 1/4; 80 ÷ 4 = 20. A) Used 80 ÷ 20 instead. B) Restated the percent. D) Used 50% by mistake.
1 cards from the 2 in this chapter.
Worked example: What percent is 18 out of 60?
Step 1: Write the part-to-whole ratio as a fraction. 18/60. Step 2: Convert the fraction to a decimal. 18 ÷ 60 = 0.3. Step 3: Multiply by 100 to express as a percent. 0.3 × 100 = 30%. Answer: 30%. Check: 30% of 60 = 0.30 · 60 = 18 ✓
These are a sample. The full Percent as a Ratio per Hundred chapter runs 36 items with per-chapter progress tracking, on the web and in the iOS app.
Open 6th Math: Ratios & Proportional Relationships in CoStudy →
All 6th Math: Ratios & Proportional Relationships practice questions →