Question

Limits and boundaries of the respective class intervals are represented by the variables a, b, c, d, e, f, g and h in the table given below.

Class interval	Lower limit	Upper limit	Lower Boundary	Upper Boundary
0-10	a	b	c	d
10-20	e	f	g	h

What is the sum of a, b, c, d, e, f, g and h?

• A. 40
• B. 80
• C. 0.0
• D. 160

Answer 1

The correct option is B 80

Limits and boundaries are same in exclusive class intervals
for example :-

limits	Boundries
0-10	0 - 10
10-20	10 - 20

In this case, we have exclusive class interval so limits and boundaries are the same.
a = lower limit of (0-10) interval = 0
b= upper limit of (0-10) interval = 10

Similarily,
e = 10
f = 20

c = a = 0
d = b = 10

g = e = 10
h = f = 20

Sum = 0 +10 + 0 + 10 + 10 + 20 +10 +20 = 80.