In his ranch, Doug Bo can place a loop of rope, called a lasso, once in every 2 throws around a cow’s neck. What is the probability that he will be able to place a lasso around a cow’s neck at least once in 5 attempts?  Choose the correct choice from the following answers
A) 1/5	B) 15/32	C) 1/2	D) 31/32	E) 1
This prompt is worded in an odd way, but essentially tells us that the probability of lasso-ing a cow is 1/2. The question asks for the probability of lasso-ing a cow AT LEAST ONCE in 5 attempts.   When it comes to probability questions, there are only 2 things that you can calculate: what you WANT to have happen OR what you DON'T WANT to have happen. Those two fractions will always add up to 1. Sometimes it's much easier to calculate what you DON'T WANT and then subtract that fraction from 1 (which will give you the probability of what you DO want).   Here, the work that would be required to calculate 1, 2, 3, 4, and 5 lasso-ings of a cow would take some time and effort. It's far easier to calculate what we DON'T WANT (0 lasso-ings) and subtract that fraction from 1.   The probability of NOT lasso-ing the cow on 5 attempts is:   (1/2)(1/2)(1/2)(1/2)(1/2) = 1/32   1 - 1/32 = 31/32   The probability of lasso-ing a cow AT LEAST ONCE in 5 attempts is 31/32   Final Answer:   31/32
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In his ranch, Doug Bo can place a loop of rope, called a lasso, once in every 2 throws around a cow’s neck. What is the probability that he will be able to place a lasso around a cow’s neck at least once in 5 attempts?