## Question 1

Which number should replace the question mark?

### Explanation

The scale is balanced. This is the case if the distances * weights are the same on both sides of the scale: (A + B) * weigth 1 + B * weight 2 = C * weigth 3 + (C + D) * weight 4.

(100 + 180) * 6 + 180 * ? = 180 * 6 + (180 + 100) * 6.
==> 1680 + 180 * ? = 2760.
==> 180 * ? = 2760 - 1680.
==> ? = (1080 / 180.
==> ? = 6.

### Question statistics

Overview
Question ID: b4DeU2Ba
Main category: Numerical Reasoning
Sub category: Weight Scales
Difficulty Level: NoneWhat is item difficulty?
Average IQ of people who answered this question: 96.31
Item Response Theory (IRT)What is Item Response Theory?
Item difficulty: None / 20What is item difficulty?
Discrimination: 2.19 What is item discrimination?
Point of Maximum Information: 55.65 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 1819 individual test takers who have answered this question.
Distractor AnalysisWhat is distractor analysis?
Average IQ of people who gave the correct answer: 97.42
Average IQ of people who gave an incorrect answer: 83.72