CTBS - Comprehensive Test of Basic Skills Mathematics Computation Questions and Answers — Questions and Answers
Question 1: An auditorium has 1,250 seats. For a school play, 78% of the seats were sold. How many seats were NOT sold?
- 975
- 22
- 275 (Correct answer)
- 125
Correct answer: 275
First, calculate the number of seats sold by finding 78% of 1,250: 0.78 * 1250 = 975 seats sold. Then, subtract the number of sold seats from the total number of seats to find the seats that were not sold: 1250 - 975 = 275.
Question 2: A carpenter has a piece of wood that is 10 1/2 feet long. He needs to cut a piece from it that is 3 2/3 feet long. After he cuts the piece, what is the length of the remaining wood?
- 7 1/6 feet
- 6 5/6 feet (Correct answer)
- 7 1/3 feet
- 6 1/2 feet
Correct answer: 6 5/6 feet
To subtract the mixed numbers, first find a common denominator for the fractions, which is 6. Convert 10 1/2 to 10 3/6 and 3 2/3 to 3 4/6. Since 3/6 is smaller than 4/6, you need to borrow from the whole number. 10 3/6 becomes 9 + 1 + 3/6 = 9 9/6. Now subtract: 9 9/6 - 3 4/6 = 6 5/6 feet.
Question 3: Solve the following expression: 3 + 2 x (6 - 1) ÷ 5
- 2
- 3
- 4
- 5 (Correct answer)
Correct answer: 5
Following the order of operations (PEMDAS/BODMAS): First, solve the parentheses (6 - 1) = 5. The expression becomes 3 + 2 x 5 ÷ 5. Next, perform multiplication and division from left to right: 2 x 5 = 10, then 10 ÷ 5 = 2. The expression is now 3 + 2. Finally, perform the addition: 3 + 2 = 5.
Question 4: A catering company needs to transport 248 dinner plates to an event. If each box can hold a maximum of 18 plates, what is the minimum number of boxes required to transport all the plates?
- 13
- 13.77
- 14 (Correct answer)
- 15
Correct answer: 14
To find the number of boxes, divide the total number of plates by the number of plates per box: 248 ÷ 18 = 13 with a remainder of 14. This means 13 boxes will be completely full, but there will be 14 plates left over. A separate box is needed for these remaining plates, so the total number of boxes required is 13 + 1 = 14.
Question 5: What is the result of 45.81 divided by 0.9?
- 5.09
- 50.9 (Correct answer)
- 509
- 0.509
Correct answer: 50.9
To divide by a decimal, move the decimal point in the divisor (0.9) one place to the right to make it a whole number (9). You must also move the decimal point in the dividend (45.81) one place to the right, making it 458.1. Now, perform the division: 458.1 ÷ 9 = 50.9.
Question 6: Which of the following fractions is equivalent to 5/8?
- 10/18
- 20/24
- 15/32
- 25/40 (Correct answer)
Correct answer: 25/40
To find an equivalent fraction, you must multiply both the numerator and the denominator by the same non-zero number. For the correct answer, 5/8 is multiplied by 5/5: (5 × 5) / (8 × 5) = 25/40. The other options do not maintain this equivalency.
CTBS - Comprehensive Test of Basic Skills Mathematics Computation Questions and Answers
An auditorium has 1,250 seats.
For a school play, 78% of the seats were sold.
How many seats were NOT sold?