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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								id: 5900f48a1000cf542c50ff9d
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								title: 'Problem 286: Scoring probabilities'
							 
						 
					
						
							
								
									
										
										
										
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								challengeType: 5
							 
						 
					
						
							
								
									
										
										
										
											2019-08-05 09:17:33 -07:00 
										
									 
								 
							 
							
								
									
										 
									 
								
							 
							
								 
							 
							
							
								forumTopicId: 301937
							 
						 
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00 
										
									 
								 
							 
							
								
									
										 
									 
								
							 
							
								 
							 
							
							
								dashedName: problem-286-scoring-probabilities
							 
						 
					
						
							
								
									
										
										
										
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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --description--
 
							 
						 
					
						
							
								
									
										
										
										
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								Barbara is a mathematician and a basketball player. She has found that the probability of scoring a point when shooting from a distance x is exactly (1 - x/q), where q is a real constant greater than 50.
							 
						 
					
						
							
								
									
										
										
										
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								During each practice run, she takes shots from distances x = 1, x = 2, ..., x = 50 and, according to her records, she has precisely a 2 % chance to score a total of exactly 20 points.
							 
						 
					
						
							
								
									
										
										
										
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								Find q and give your answer rounded to 10 decimal places.
							 
						 
					
						
							
								
									
										
										
										
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								# --hints--
 
							 
						 
					
						
							
								
									
										
										
										
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								`euler286()`  should return 52.6494571953.
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								assert.strictEqual(euler286(), 52.6494571953);
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --seed--
 
							 
						 
					
						
							
								
									
										
										
										
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								## --seed-contents--
 
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								function euler286() {
							 
						 
					
						
							
								
									
										
										
										
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								  return true;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								}
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								euler286();
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --solutions--
 
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								// solution required
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							 
							
							
								```