FREE IBEW Aptitude Test Number Sequences and Functions Questions and Answers

Question 1

An electrical signal's voltage is modeled by the function V(t) = 2t² - 8. At what positive value of t does the voltage equal 42?

Accepted Answer

t = 5

Answer

To solve for t, set the function equal to 42: 2t² - 8 = 42. First, add 8 to both sides to get 2t² = 50. Then, divide both sides by 2 to get t² = 25. Finally, take the square root of both sides. Since the question asks for a positive value, t = 5.

Question 2

What is the next number in the following sequence: 3, 7, 16, 32, 57, ...?

Accepted Answer

93

Answer

The pattern is based on adding the square of consecutive integers. The difference between 3 and 7 is 4 (2²). The difference between 7 and 16 is 9 (3²). The difference between 16 and 32 is 16 (4²). The difference between 32 and 57 is 25 (5²). The next step is to add 6², which is 36. So, 57 + 36 = 93.

Question 3

The function f(x) represents the number of feet of wire an apprentice can install in 'x' hours. If f(x) = 50x - 5, which of the following statements is true?

Accepted Answer

After 4 hours, the apprentice will have installed 195 feet of wire.

Answer

To find the amount of wire installed after 4 hours, substitute x=4 into the function: f(4) = 50(4) - 5. This calculates to 200 - 5 = 195. Therefore, the apprentice will have installed 195 feet of wire.

Question 4

A wiring project's progress can be tracked by the sequence: 5, 12, 19, 26, 33. This represents the number of circuits completed each day. Which function, C(d), correctly models the number of circuits completed on day 'd'?

Accepted Answer

C(d) = 7d - 2

Answer

This is an arithmetic sequence with a common difference of 7. The formula for the nth term of an arithmetic sequence is a_n = a_1 + (n-1)d. Here, a_1 = 5, n=d, and d=7. So, C(d) = 5 + (d-1)7 = 5 + 7d - 7 = 7d - 2. We can check this: C(1)=7(1)-2=5, C(2)=7(2)-2=12, C(3)=7(3)-2=19.

Question 5

Identify the pattern and find the missing number in the sequence: 81, 27, __, 3, 1.

Accepted Answer

9

Answer

This is a geometric sequence where each term is found by dividing the previous term by 3. 81 / 3 = 27. 27 / 3 = 9. 9 / 3 = 3. 3 / 3 = 1. The missing number is 9.

IBEW - Aptitude Test Practice Test

IBEW - Aptitude Test Practice Test

FREE IBEW Aptitude Test Number Sequences and Functions Questions and Answers