Question
Download Solution PDFThe students of a class are made to stand equally in rows. If 3 students are extra in each row, there would be 1 row less. If 3 students are less in a row, there would be 2 more rows. Then the number of students in the class would be
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Let S be the total number of students in the class.
Let R be the original number of rows.
Let N be the original number of students in each row.
Total students (S) = R × N
Condition 1: If 3 students are extra in each row, there would be 1 row less.
New number of students per row = N + 3
New number of rows = R - 1
Total students (S) = (R - 1) × (N + 3)
Condition 2: If 3 students are less in a row, there would be 2 more rows.
New number of students per row = N - 3
New number of rows = R + 2
Total students (S) = (R + 2) × (N - 3)
Calculations:
From Condition 1:
RN = (R - 1)(N + 3)
RN = RN + 3R - N - 3
0 = 3R - N - 3
⇒ N = 3R - 3 (Equation 1)
From Condition 2:
RN = (R + 2)(N - 3)
RN = RN - 3R + 2N - 6
0 = -3R + 2N - 6
⇒ 3R - 2N = -6 (Equation 2)
Now, substitute Equation 1 into Equation 2:
3R - 2(3R - 3) = -6
3R - 6R + 6 = -6
-3R = -6 - 6
⇒ R = 4
Now, substitute the value of R back into Equation 1 to find N:
N = 3R - 3
N = 3(4) - 3
N = 12 - 3 = 9
Total number of students (S) = R × N = 4 × 9 = 36
∴ The number of students in the class would be 36.
Last updated on Feb 11, 2025
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