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.
Intern
Joined: 20 Jun 2021
Posts: 21
Given Kudos: 152
WE:Manufacturing and Production (Manufacturing)
If the sum of the consecutive integers from –42
[#permalink]
07 Aug 2021, 17:04
07 Aug 2021, 17:04
00:00
Question Stats:
75% (01:27) correct
25% (01:54) wrong based on 8 sessions
Hide Show timer Statistics
If the sum of the consecutive integers from –42 to n inclusive is 372, what is the value of n?
A. 47
B. 48
C. 49
D. 50
E. 51
A. 47
B. 48
C. 49
D. 50
E. 51
If the sum of the consecutive integers from –42
[#permalink]
07 Aug 2021, 19:59
07 Aug 2021, 19:59
1
Consecutive integers from \(-42\) to \(n\), the sum is \(372\)
When there are consecutive integers then the sum of the numbers between \(-42\) to \(42\) will be zero.
From \(43, 44, 45,...\) the sum of the series will be \(372\).
The sum of the series, when last digit is known = \(S_n =\) \(\frac{n}{2} (2a + (n-1)d)\)
\(a =\) first term & \(d =\) common difference
\(372 = \frac{n}{2} (2(43) + (n-1))\)
By solving this, the answer of \(n\) will be \(8\), which means that the no will be \(50\)
OR
you can try adding nos \(43, 44, 45,...\) up until the sum is \(372\) and the last no will be \(50\)
Answer D
When there are consecutive integers then the sum of the numbers between \(-42\) to \(42\) will be zero.
From \(43, 44, 45,...\) the sum of the series will be \(372\).
The sum of the series, when last digit is known = \(S_n =\) \(\frac{n}{2} (2a + (n-1)d)\)
\(a =\) first term & \(d =\) common difference
\(372 = \frac{n}{2} (2(43) + (n-1))\)
By solving this, the answer of \(n\) will be \(8\), which means that the no will be \(50\)
OR
you can try adding nos \(43, 44, 45,...\) up until the sum is \(372\) and the last no will be \(50\)
Answer D
gmatclubot
If the sum of the consecutive integers from –42 [#permalink]
07 Aug 2021, 19:59
Moderators:
