A. 10
B. 11.5
C. 12
D. 10.5
Explanation:
Average of the first ‘n’ natural numbers = (n + 1)/2
We get (20 + 1)/2 = 10.5
A. 26
B. 28
C. 30
D. 32
Explanation:
Let A = Set of students who fail in English
B = Set of students who fair in mathematics
Then , n(A) = 50, n(B) = 30 and n(A∩ B) = 12.
n(AUB) = n(A) + n(B)- n(A∩B) = (50 + 30 -12) = 68
Number of students who fail in one or both the students = 68
Number of those who pass in both = (100 – 68) = 32
A. 17 kg
B. 20 kg
C. 26 kg
D. 31 kg
Let A, B, C represent their respective weights. Then, we have: A + B + C = (45 x 3) = 135 …. (i) A + B = (40 x 2) = 80 …. (ii) B + C = (43 x 2) = 86 ….(iii) Adding (ii) and (iii), we get: A + 2B + C = 166 …. (iv) Subtracting (i) from (iv), we get : B = 31. B’s weight = 31 kg
A. 1.5 months
B. 40 days
C. 2 months
D. 50 days
A. 6 hrs 21 min
B. 6 hrs 24 min
C. 6 hrs 27 min
D. 6 hrs 30 min
Time taken to cover 600 km = ( 600/100 ) hrs = 6 hrs. Number of stoppages = ( 600/75 – 1 ) = 7 Total time of stoppage = (3 x 7) min = 21 min. Hence, total time taken = 6 hrs 21 min.
A. 11
B. 10
C. 12
D. 17
Sum of 10 odd no. = 100
Average = 100/10 = 10
A. 6s
B. 2.08s
C. 7.5s
D. 8s
60 km/hr = 60 * 5/18 = 16.67 m/s
Speed = distance/time; v = d/t
16.67 = 125/t
t = 7.5s