x, y, and z are consecutive integers, and x < y < z. What is the average of x, y, and z?
(1) x = 11
(2) The average of y and z is 12.5.
The OA is the option _D_
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x, y, and z are consecutive integers, and x < y < z.
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Your Answer
A
B
C
D
E
Global Stats
1. Clearly sufficient.
2. Take 3 numbers
\(a-d\, a\, a+d\)
avg \(=\frac{ a-d + a + a+d}{3} = \frac{3a}{3} = a\)
Hence we need to know \(a\) only... \(d\) is 1
now \(\frac{y+z}{2} = \frac{25}{2}\)
\(a+a+d = 25\)
\(2a+1 = 25\)
\(a =\frac{24}{2} \Rightarrow 12 \)
Hence sufficient.
So the answer is __D__
2. Take 3 numbers
\(a-d\, a\, a+d\)
avg \(=\frac{ a-d + a + a+d}{3} = \frac{3a}{3} = a\)
Hence we need to know \(a\) only... \(d\) is 1
now \(\frac{y+z}{2} = \frac{25}{2}\)
\(a+a+d = 25\)
\(2a+1 = 25\)
\(a =\frac{24}{2} \Rightarrow 12 \)
Hence sufficient.
So the answer is __D__
