If a quality control check is made by inspecting a sample of 2 lightbuls from a box of 12, how many different samples can be chosen?
A. 6
B. 24
C. 36
D. 66
E. 72
Answer is D
Please explain, thank you !
How many different samples can be chosen???
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Samples can be chosen in 12C2 = 12!/[2! * (12 - 2)!] = (12 * 11 * 10!)/[2 * 10!]gmatpup wrote:If a quality control check is made by inspecting a sample of 2 lightbuls from a box of 12, how many different samples can be chosen?
A. 6
B. 24
C. 36
D. 66
E. 72
Answer is D
Please explain, thank you !
= 6 * 11 = 66
The correct answer is D.
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The number of samples that can be chosen is:gmatpup wrote:If a quality control check is made by inspecting a sample of 2 lightbuls from a box of 12, how many different samples can be chosen?
A. 6
B. 24
C. 36
D. 66
E. 72
12C2 = 12!/(2! x 10!) = (12 x 11)/2! = 66
Answer: D
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