GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
The average of the numbers a, b, c, 5, 15 is s and the average of th
[#permalink]
15 Oct 2024, 00:03
15 Oct 2024, 00:03
Expert Reply
00:00
Question Stats:
100% (01:17) correct
0% (00:00) wrong based on 3 sessions
Hide Show timer Statistics
The average of the numbers a, b, c, –5, –15 is s and the average of the numbers a, b, c, 5, 15 is t. What is the value of (s–t)?
A. –8
B. –5
C. –1
D. 0
E. 5
A. –8
B. –5
C. –1
D. 0
E. 5
- Part of the project: GRE Quant & Verbal ADVANCED Daily Challenge 2024 Edition - Gain 20 Kudos & Get FREE Access to GRE Prep Club TESTS
- Also replying to the unanswered questions
Re: The average of the numbers a, b, c, 5, 15 is s and the average of th
[#permalink]
16 Dec 2024, 13:52
16 Dec 2024, 13:52
Expert Reply
We know that the average of 5 numbers $\(a, b, c,-5 \&-15\)$ is $\(s\)$, so we get $\(\frac{a+b+c+(-5)+(-15)}{5}=s \Rightarrow a+b+c=5 s+20 \ldots . .(1)\)$
Also as the average of 5 numbers $\(a, b, c, 5 \& 15\)$ is $\(t\)$, we get $\(\frac{\mathrm{a}+\mathrm{b}+\mathrm{c}+5+15}{5}=\mathrm{t} \Rightarrow \mathrm{a}+\mathrm{b}+\mathrm{c}=5 \mathrm{t}-20 \ldots\)$.
Now, using (1) \& (2), we get $\(5 \mathrm{~s}+20=5 \mathrm{t}-20\)$, which gives $\(s-t=\frac{-20-20}{5}=\frac{-40}{5}=-8\)$
Hence the answer is (A).
Also as the average of 5 numbers $\(a, b, c, 5 \& 15\)$ is $\(t\)$, we get $\(\frac{\mathrm{a}+\mathrm{b}+\mathrm{c}+5+15}{5}=\mathrm{t} \Rightarrow \mathrm{a}+\mathrm{b}+\mathrm{c}=5 \mathrm{t}-20 \ldots\)$.
Now, using (1) \& (2), we get $\(5 \mathrm{~s}+20=5 \mathrm{t}-20\)$, which gives $\(s-t=\frac{-20-20}{5}=\frac{-40}{5}=-8\)$
Hence the answer is (A).
Re: The average of the numbers a, b, c, 5, 15 is s and the average of th
[#permalink]
16 Dec 2024, 13:52
16 Dec 2024, 13:52
Expert Reply
We know that the average of 5 numbers $\(a, b, c,-5 \&-15\)$ is $\(s\)$, so we get $\(\frac{a+b+c+(-5)+(-15)}{5}=s \Rightarrow a+b+c=5 s+20 \ldots . .(1)\)$
Also as the average of 5 numbers $\(a, b, c, 5 \& 15\)$ is $\(t\)$, we get $\(\frac{\mathrm{a}+\mathrm{b}+\mathrm{c}+5+15}{5}=\mathrm{t} \Rightarrow \mathrm{a}+\mathrm{b}+\mathrm{c}=5 \mathrm{t}-20 \ldots\)$.
Now, using (1) \& (2), we get $\(5 \mathrm{~s}+20=5 \mathrm{t}-20\)$, which gives $\(s-t=\frac{-20-20}{5}=\frac{-40}{5}=-8\)$
Hence the answer is (A).
Also as the average of 5 numbers $\(a, b, c, 5 \& 15\)$ is $\(t\)$, we get $\(\frac{\mathrm{a}+\mathrm{b}+\mathrm{c}+5+15}{5}=\mathrm{t} \Rightarrow \mathrm{a}+\mathrm{b}+\mathrm{c}=5 \mathrm{t}-20 \ldots\)$.
Now, using (1) \& (2), we get $\(5 \mathrm{~s}+20=5 \mathrm{t}-20\)$, which gives $\(s-t=\frac{-20-20}{5}=\frac{-40}{5}=-8\)$
Hence the answer is (A).
