56. If 22nd April 2013 is Monday, then what was the day of the week on 22nd April 2012?
(A) Sunday
(B) Saturday
(C) Tuesday
(D) Wednesday
Answer:
(A) Sunday
Explanation:
Because the period from 22 April 2012 to 22 April 2013 does not include February 2012 (the leap day), there are exactly 365 days between them. 365 days yields 1 odd day. Going backwards, Monday minus 1 day is Sunday.
57. The last day of a century cannot be
(A) Monday
(B) Wednesday
(C) Tuesday
(D) Friday
Answer:
(C) Tuesday
Explanation:
100 years contain 5 odd days (Friday). 200 years contain 3 odd days (Wednesday). 300 years contain 1 odd day (Monday). 400 years contain 0 odd days (Sunday). Therefore, a century can only end on Sunday, Monday, Wednesday, or Friday. It can never be Tuesday, Thursday, or Saturday.
58. The average of A, B and C is 50. If D is 10, then what is the average of A, B, C and D?
(A) 15
(B) 40
(C) 30
(D) 60
Answer:
(B) 40
Explanation:
Since the average of 3 numbers is 50, their sum is 3 * 50 = 150. If D is 10, the total sum of all four numbers is 150 + 10 = 160. The new average is 160 / 4 = 40.
59. A man’s monthly income is Rs. 1400. What should be his average monthly expenditure so that he is able to save Rs. 3600 in a year?
(A) 1000
(B) 1100
(C) 1150
(D) 1200
Answer:
(B) 1100
Explanation:
Total annual income = 1400 * 12 = 16800. If he saves 3600 per year, his total annual expenditure is 16800 – 3600 = 13200. His average monthly expenditure is 13200 / 12 = 1100.
60. A car owner buys petrol at Rs. 8 and Rs. 10 for two successive years. What approximately is the average cost per litre of petrol if he spends Rs. 4000 each year?
(A) 9
(B) 9.90
(C) 8.88
(D) 10
Answer:
(C) 8.88
Explanation:
In year 1, he bought 4000/8 = 500 liters. In year 2, he bought 4000/10 = 400 liters. Total spent = 8000. Total liters = 900. Average cost = 8000 / 900 = 80 / 9 ≈ 8.88.
