IBEW Fractions, Decimals, and Percentages 2 — Questions and Answers
Question 1: Convert 7/8 to a decimal.
- 0.785
- 0.875 (Correct answer)
- 0.750
- 0.825
Correct answer: 0.875
7 ÷ 8 = 0.875.
To convert a fraction to a decimal, divide the numerator by the denominator: 7 ÷ 8 = 0.875. You can verify: 0.875 × 8 = 7 ✓. Common fractions and their decimal equivalents should be memorized for speed on aptitude tests.
Question 2: What is 3/4 + 5/6?
- 8/10
- 19/12 (Correct answer)
- 8/12
- 13/12
Correct answer: 19/12
LCD = 12. 3/4 = 9/12 and 5/6 = 10/12. Sum = 19/12.
The LCD of 4 and 6 is 12. Convert: 3/4 = 9/12, 5/6 = 10/12. Add: 9/12 + 10/12 = 19/12 (or 1 and 7/12). Always find the LCD before adding or subtracting fractions.
Question 3: A price increases from $80 to $92. What is the percentage increase?
- 13%
- 14%
- 15% (Correct answer)
- 12%
Correct answer: 15%
Increase = $12. Percentage = (12/80) × 100 = 15%.
Percentage increase = [(new - original) ÷ original] × 100 = [(92 - 80) ÷ 80] × 100 = [12 ÷ 80] × 100 = 0.15 × 100 = 15%.
Question 4: Subtract: 5/6 - 2/9
- 3/3
- 11/18 (Correct answer)
- 7/18
- 1/2
Correct answer: 11/18
LCD = 18. 5/6 = 15/18 and 2/9 = 4/18. Difference = 11/18.
LCD of 6 and 9 is 18. Convert: 5/6 = 15/18, 2/9 = 4/18. Subtract: 15/18 - 4/18 = 11/18. This fraction is already in simplest form since 11 is prime and does not divide 18.
Question 5: What is 0.625 as a fraction in lowest terms?
- 625/1000
- 5/8 (Correct answer)
- 3/5
- 6/10
Correct answer: 5/8
0.625 = 625/1000. Simplify by dividing by 125: 5/8.
0.625 = 625/1000. GCD of 625 and 1000 is 125. 625÷125=5 and 1000÷125=8. So 0.625 = 5/8. Verify: 5÷8=0.625 ✓.
Question 6: If 40% of a number is 60, what is the number?
- 120
- 140
- 150 (Correct answer)
- 160
Correct answer: 150
Let n = the number. 0.40 × n = 60. n = 60 ÷ 0.40 = 150.
If 40% of n = 60, then 0.40n = 60. Dividing both sides by 0.40: n = 60 ÷ 0.40 = 150. Check: 40% of 150 = 0.40 × 150 = 60 ✓.
IBEW Fractions, Decimals, and Percentages 2
Convert 7/8 to a decimal.