56. The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is:
a) 17 kg
b) 20 kg
c) 26 kg
d) 31 kg
57. The average monthly income of p and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is:
a) Rs. 3500
b) Rs. 4000
c) Rs.4050
d) Rs. 5000
58. The average age of 36 students in a group is 14 years. When teacher’s age is included to it, the average increases by one. What is the teacher’s age in year?
a) 31
b) 36
c) 51
d) Cannot be determined
e) None of these
59. The average monthly salary of 20 employees in an organization is Rs. 1500. If the manager’s salary is added, then the average salary increases by Rs. 100. What is the manager’s monthly salary?
a) Rs. 2000
b) Rs. 2400
c) Rs. 3600
d) Rs. 4800
60. The average weighty of a class of 24 students is 35 kg. if the weight of the teacher be included, the average rises by 400 g. the weight of the teacher is:
a) 45 kg
b) 50 kg
c) 53 kg
d) 55 kg
ANSWERS
56.D
57.B
58.C
59.C
60.A
SOLUTION
56. Let A, B, C represent their respective weights. Then, we have:
A + N + C = (45 x 3) = 135
A + B = (40 x 2) = 80
B + C = (43 x 2) = 86.
Adding (II) and (III), we get: A + 2B + C =166
Subtracting (I) from (IV), we get: B = 31.
B’s weight = 31 kg.
57. Let P, Q and R represent their respective monthly incomes. Then, we have:
P + Q (5050 x 2) = 10100
Q + R = (6250 x 2) = 12500
P + R = (5200 x 2) = 10400
Adding (I), (II) and (III), we get: 2 (P + Q + R) = 33000 – or P + Q + R = 16500.(IV) subtracting (II) from (IV), we get P = 4000.
P’s monthly income = Rs. 4000.
58. Age of the teacher = (37 x 15 – 36 x 14) years = 51 years.
59. Manager’s monthly salary = Rs. (1600 x 21 – 1500 x 20) = Rs. 3600.
60. Weight of the teacher =(35.4 x 25 – 35 x 24) kg = 45 kg.
No comments:
Post a Comment