Solutions
Get detailed explanations to advanced GMAT questions.
Question
If the sum of the consecutive integers from –42 to n inclusive is 372, what is the value of n?
Option A:
47
Option B:
48
Option C:
49
Option D:
50
Option E:
51
Difficulty Level
MediumSolution
Option D is the correct answer.
Option Analysis
Number of terms =42+1+n=(n+43)
To find the sum = Formula = (n/2)(a+l), where n is the number of terms and ‘a’ and ‘l’ is the first term and last term.
Sum=372=((n+43)∗(n−42))/2
744=(n+43)∗(n−42) n=50
OR
42 terms after zero and 42 terms below zero will total 0. So, our new question will be consecutive integers with first term 43 have sum 372, what is the last term: ((43+n)/2)∗(n−43+1)=372 (n+43)∗(n−42)=744 n=50
Related Questions
- A total of 800 students were asked whether they found two subjects, M and R, interesting. Each answer…
- A certain cake has two layers with pieces of fruit on top of each layer. Of all the pieces of fruit on…
- A string of 10 light bulbs is wired in such a way that if any individual light bulb fails, the entire string…
- In a particular machine, there are 2 gears that interlock; one gear is larger in circumference than the…
- The ratio of R to S is 3 to 5, what is the value of the ratio (R + K)/(S + K)?