Finding the Largest Even Integer in a Sequence
Understanding the Problem: Sum of Consecutive Even Integers
The goal is to find the largest integer in a sequence of fifty consecutive even integers, given that their sum is 3250. This problem can be approached using the principles of arithmetic series and basic algebra. Let's break down the steps and solve it using different methods.
Step-by-Step Solution Using Algebra
To find the largest of the fifty consecutive even integers, let's denote the first integer in the sequence as x. The sequence would then be:
x, x 2, x 4, ..., x 98The sum of these integers can be formulated as:
S x (x 2) (x 4) ... (x 98)
This is an arithmetic series where:
First term (a) x Last term (l) x 98 Number of terms (n) 50The sum of an arithmetic series can be calculated using the formula:
S (n/2) * (a l)
Substituting the values, we get:
S (50/2) * (x (x 98)) 25 * (2x 98) 5 2450
We are given that the sum S is 3250:
5 2450 3250
Solving for x, we get:
5 800
x 16
Therefore, the first integer in the sequence is 16. The largest integer in the sequence is:
x 98 16 98 114
Using the J Programming Language
To verify the solution using a different approach, we can use the J programming language to generate all possible sets of 50 consecutive even integers from 1 to 1000 and find the one that sums to 3250. The code can be written as:
./n~3250 114
The answer is 114, which confirms our earlier calculation.
Using the Concept of Triangular Numbers
Another method involves recognizing that the sum of the first 50 even numbers is 2450. We can use the sum of the first 49 triangular numbers:
1 2 3 ... 49 (49 * 50) / 2 1225
Multiplying by 2 to convert these triangular numbers into even numbers, we get:
2 * 1225 2450
The sum we need is 3250, so we calculate:
3250 - 2450 800
x 800 / 50 16
The largest integer in the sequence is:
x 98 16 98 114
Thus, the largest integer in the sequence is 114.