An assembly has x rows, with (x+17) chairs in each row. If there are 1568 chairs in total, how many rows are there?
Answer and explanation
Correct answer: 32
The total-chair condition gives x(x+17)=1568. Thus, x²+17x−1568=0, which factors as (x−32)(x+49)=0. Hence x=32 or x=−49. Since the number of rows cannot be negative, x=32 is the valid answer. Exam tip: In arrangement problems, reject negative roots and retain the positive integer root.
Frequently asked questions
What is the correct answer to this question?
32
Why is this the correct answer?
The total-chair condition gives x(x+17)=1568. Thus, x²+17x−1568=0, which factors as (x−32)(x+49)=0. Hence x=32 or x=−49. Since the number of rows cannot be negative, x=32 is the valid answer. Exam tip: In arrangement problems, reject negative roots and retain the positive integer root.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Word Problems and Applications.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
