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  • NDA Exam Mathematics Study Material

Digitization help student to explore and study their academic courses online, as this gives them flexibility and scheduling their learning at their convenience. Kidsfront has prepared unique course material of Mathematics Statistical for NDA Exam student. This free online Mathematics study material for NDA Exam will help students in learning and doing practice on Statistical topic of NDA Exam Mathematics. The study material on Statistical, help NDA Exam Mathematics students to learn every aspect of Statistical and prepare themselves for exams by doing online test exercise for Statistical, as their study progresses in class. Kidsfront provide unique pattern of learning Mathematics with free online comprehensive study material and loads of NDA Exam Mathematics Statistical exercise prepared by the highly professionals team. Students can understand Statistical concept easily and consolidate their learning by doing practice test on Statistical regularly till they excel in Mathematics Statistical.


Statistical
Find the mean of the first 6 prime numbers?

a) 15 / 3
b) 6
c) 41 / 6
d) 12 /4



Answer
Solution
Correct Answer Is : 41 / 6
Solution Is : The first 6 prime numbers are 2 , 3 , 5 , 7 ,11 , 13 Mean = ( 2 + 3 + 5 + 7 + 11 + 13 ) / 6 = 41 / 6
The mean proportion of 1.21 and 0.09 is

a) 0.33
b) 3.03
c) 3.3
d) 0.033



Answer
Solution
Correct Answer Is : 0.33
Solution Is : Mean proportion = √ab here, a=121 and b= 0.09 So, Mean proportion = √121*0.09 = √121/100 * 9/100 √11*11/10*10 * 3*3/10*10 = 11*3/100 = 33/100 = 0.33.
The arithmetic mean (average) of the first 10 whole numbers is

a) 5
b) 4
c) 5.5
d) 4.5



Answer
Solution
Correct Answer Is : 4.5
Solution Is : (4) Required average =(0+1+2+3+?+9)/10 =(9*(9+1))/(2*10) 4.5
The mean of 9 observations is 16. One more observation is included and the new mean becomes 17. The 10th observation is

a) 9
b) 16
c) 26
d) 30



Answer
Solution
Correct Answer Is : 26
Solution Is : (3) Tricky Approach Tenth observation =10*17-16*9 =170-144 =26
The average of x numbers is y and average of y numbers is x. Then , the average of all the numbers taken together is

a) (x+y )/ 2xy
b) 2xy / (x+y)
c) (x2 + y2) /(x+y)
d) Xy/(x+y)



Answer
Solution
Correct Answer Is : 2xy / (x+y)
Solution Is : Average of x nuber is y . Sum of x numbers = x * y = xy Similarly , average of y numbers is x , Sum of y numbers = y * x = xy Sum of total numbers = xy + xy = 2xy Average of totasl numbers = 2xy / (x+y)
The mean value of 20 observation was found to 75, but later on it was detected that 97 was misread as 79. Find the correct mean.

a) 75.7
b) 75.8
c) 75.9
d) 75.6



Answer
Solution
Correct Answer Is : 75.9
Solution Is :
Given the mean of five numbers is 27. If one of them is excluded , the mean gets reduced by 2. Determine the excluded number.

a) 45
b) 55
c) 25
d) 35



Answer
Solution
Correct Answer Is : 35
Solution Is : Mean of 5 numbers = 27
Sum of 5 numbers = 27x5 = 135
Now , Mean of 4 numbers after exclusion of a number = 25
Sum of 4 numbers = 25 x 4 = 100
Excluded number = Sum of 5 numbers - sum of 4 numbers
= 135 - 100 = 35
If x is the mean of n observations x1 , x2 ,

a) X
b) A x
c) X/a
d) X + a



Answer
Solution
Correct Answer Is : X/a
Solution Is : When each number is divided by `a` then mean is also divided by `a`
New mean = x/a
The mean weight of 34 students of a school is 42 kg. If the weight of the teacher be included, the mean rises by 400 g. find the weight of the teacher in kg

a) 66
b) 56
c) 55
d) 57



Answer
Solution
Correct Answer Is : 56
Solution Is : Total weight of student = number of student x avearege =34x42=1428kg
now,when teacher is included
total member = 34+1=35
Average Weight =42+0.400=42.4kg
similarly their total weight = 42.4x35=1484kg
therefore weight of teacher =(total weight including teacher -
total weight excluding teacher)
= 1484-1428 = 56 kg
Study the chart and answer the following question

Themean of the highest and the lowest sale (in rs crore )is

a) 4922
b) 4922.5
c) 4827
d) 4365



Answer
Solution
Correct Answer Is : 4827
Solution Is : Mean = Highest sale +
Lowest sale / 2
= 8730 + 924 / 2
= 4827 core