Answers IQ test

Question 7

image/svg+xml 15 135 120 -15 -135 ?
What is the next number in this sequence?

Explanation

The next number in the sequence is always found by subtracting the number before the previous number from the previous number. So you calculate the number in position 3 by subtracting the number in position 1 from the number in position 2.

Watch out, subtracting a negative number is the same as adding the number.
135 - 15 = 120
120 - 135 = -15
-15 - 120 = -135
-135 - -15 = -120
image/svg+xml 15 135 120 -15 -135 ?

Question statistics

Overview
Question ID: pXRJWtH6
Main category: Numerical Reasoning
Sub category: Number sequences
Difficulty Level: 6What is item difficulty?
Nr of times answered: 2881
Average IQ of people who answered this question: 93.51
Percentage of answers correct: 80.56%
Item Response Theory (IRT)What is Item Response Theory?
Item difficulty: 6 / 20What is item difficulty?
Discrimination: 2.38 What is item discrimination?
Point of Maximum Information: 77.70 What is Point of Maximum Information?
Item Characteristic Curve (ICC)
This Item Characteristic Curve shows the probability that a person with a given IQ level will correctly answer this question. This graph is based on the answers and the IQ levels of 2881 individual test takers who have answered this question.
Distractor AnalysisWhat is distractor analysis?
Average IQ of people who gave the correct answer: 96.53 Why does the average IQ of people who answer the questions differ per question?
Average IQ of people who gave an incorrect answer: 83.13
Response Time AnalysisWhat is response time analysis?
Optimal time to spend on question: 33 seconds What is the optimal response time?
Optimal time to spend on question
The graph illustrates the last 250 correct and incorrect answers to this question, as well as the time it took for test takers to arrive at the answer. Using this data, an average optimal time for answering the question is calculated. However, it should be noted that the optimal time may vary for individual test takers.

Time spent: you used 11 seconds to answer this question