Shortcut Trick
To minimize the total sections, the number of students per section must be maximum.
Maximum students per section = HCF of (188, 282, 423) = 47.
Total sections = (188 ÷ 47) + (282 ÷ 47) + (423 ÷ 47)
Total sections = 4 + 6 + 9 = 19
∴ The correct answer is 19 sections.
Alternate Method
Given:
Number of students in 4th class = 188
Number of students in 5th class = 282
Number of students in 6th class = 423
Formula Used:
Minimum sections = Total students in each class ÷ Maximum capacity per section
Maximum capacity per section = HCF of the number of students in all given classes.
Class 4
188 students → 4 sec
Class 5
282 students → 6 sec
Class 6
423 students → 9 sec
Total Sections = 4 + 6 + 9 = 19
Calculations:
⇒ First, calculate the HCF of 188, 282, and 423 using the difference method.
⇒ Difference between 282 and 188 = 94
⇒ Difference between 423 and 282 = 141
⇒ The difference between these two results (141 − 94) = 47
⇒ Checking divisibility: 188 ÷ 47 = 4, 282 ÷ 47 = 6, 423 ÷ 47 = 9
⇒ Hence, the HCF is 47, which means each section has exactly 47 students.
⇒ Number of sections in class 4 = 188 ÷ 47 = 4
⇒ Number of sections in class 5 = 282 ÷ 47 = 6
⇒ Number of sections in class 6 = 423 ÷ 47 = 9
⇒ Total minimum number of sections = 4 + 6 + 9 = 19
∴ The correct answer is 19 sections.
Additional Information
Highest Common Factor (HCF)
HCF is the largest positive integer that divides all the given numbers without leaving a remainder. It is practically used when dividing items, groups, or lengths into the largest possible equal segments.
Difference Method for HCF
The HCF of given numbers is always a factor of the difference between any two of those numbers. Calculating differences helps skip long factorisations and quickly locates the HCF.
Least Common Multiple (LCM)
LCM is the smallest integer that is a multiple of all given numbers. Unlike HCF, which breaks down numbers into groups, LCM builds them up to find a common matching point.