Question

The width of each of five continuous classes in a frequency distribution is 5 and the lower class limit of the lowest class is 10. The upper class limit of the highest class is
A. 15
B. 25
C. 35
D. 40

Answer 1

Correct Answer - C
Let x and y be the upper and lower class limit of frequency distribution.
Given, width of the class =5
`rArr x-y=5` ……….(i)
Also, given lower class (y)=10
On putting y=10 in Eq. (i), we get
`x-10=5 rArr x=15`
So, the upper class limit of the lowest class is 15.
Hence, the upper limit of the highest class
= (Number of continuous classes x Class with + Lower class limit of the lowest class)
`=5 xx 5 + 10 = 25+10=35`
Hence, the upper class limit of the highest class is 35.
Alternate method
After finding the upper class limit of the lowest class, the five continuous classes in a frequency distribution with width 5 are 10-15, 15-20, 20-25, 25-30, and 30-35.
Thus, the highest class is 30-35,
Hence, the upper limit of the class is 35.