In the class intervals 10-20, 20-30, the number is included in :
(A) 10-20
(B) 20-30
(C) both the intervals
(D) none of these intervals
Answer : B
Here, in these class intervals 10-20,20-30, the number 20 is included in 20-30,
Because in 10-20 there are only (10, 11....19)
And in 20-30 there are only (20, 21,.....29)
Hence we don’t count the upper limit in every class interval.
The number is always included in the lower limit of the class interval.
Therefore option (B) is correct.