Answer:
70 students
Step-by-step explanation:
As, 30% Mike surveyed
And these 30% are 21 students
So 30% of X = 21
= 30/100 x X = 21
= 30X = 2100
So X = 2100/30
X = 70
So 70 students were surveyed
Answer:
A. 2x-4
Step-by-step explanation:
Let his brother's age be 
.
Derrick is 4 years younger than twice his brother's age. Which means derrick is 4 years younger than 
.
Which makes derricks age 
since he is 4 years younger
Answer:
,50
Step-by-step explanation:
you are supposed to multiply 5 and 10
Answer: (a) 9
Step-by-step explanation:
We are given that ,
The first two classes of a frequency distribution are 0-9 and 10-19.
We know that the class width of an class interval is basically the difference between the upper limit and the lower limit of the interval.
For example the class interval for interval 40 - 45 is 5 because 45-40=5.
For the given class interval 0-9 , upper limit= 9
Lower limit =0
⇒ Class width = 9-0= 9
Similarly , for 10-19 , the class width = 19-10=9
Therefore , the class width is 9 .
Hence, the correct answer is (a) 9.
The answer is B
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