How many triangles can be formed by joining 3 of 10 points, no three of which lie on a line?
Answer and explanation
Correct answer: B.
- Step 1: A triangle is a choice of 3 points: .
- Step 2: .
Answer
.
Why not the others: : The order of the vertices was counted. : was multiplied by 3. : Pairs of points were counted.
Practise more Logical, Spatial and Cognitive Reasoning.
Free questions with an explanation for every one, and full timed Egyptian STEM Schools Admissions Assessment mock tests.
More Logical, Spatial and Cognitive Reasoning questions
- Find the missing number in the sequence: .
- If all Bloops are Razzies, and all Razzies are Lizzies, which statement MUST be logically true?
- A clock viewed in a plane mirror shows the time as 3:45. What is the actual time on the clock?
- In a code language, if 'PLANET' is written as 'QMBOFU', how is 'ROCKET' written in the same code?
- Pointing to a photograph, a woman says: 'His mother is the only daughter of my mother.' How is the woman related to the person in the photog…
- If a standard six-sided die is rolled, what is the probability of obtaining either a prime number or an even number?