q: In digging a grave 200 m * 100 m * 3 m the volumes of the dirt to be extracted will be?
Options:
(A) 600 cu.m
(B) 12000 cu.m
(C) 6000 cu.m
(D) 60000 cu.m
(E) 4000 cu.m
a: OK... 200 * 100 * 3 = 60000
The answer is (D).

q: In Sam's hanger there are 23 boxes, 16 out of the boxes are filled with toys and the rest are filled with electrical appliances. 8 boxes are for sale, 4 of them are filled with toys. How many boxes with electrical appliances are in Sam's hanger that is not for sale?
Options:
(A) 1.
(B) 2.
(C) 3.
(D) 4.
(E) 5.
a: OK... Total boxes = 23
Filled with toys = 16
Filled with appliance = 7
Total boxes for sale = 8
Toy boxes for sale = 4
Appliance boxes for sale = 4
Appliance boxes not for sale = 7 - 4 = 3
The answer is (C).

q: A can do a piece of work in 20 days. B in 15 days A and C in 12 days. In how many days can A finish the work if he is assisted by B on one day and C on the next, alternately?
Options:
(A) 7 days
(B) 8 days
(C) 3 days
(D) 9 days
(E) 2 days
a:
OK... A + B = 1/20 + 1/15 = 7/60
A + C = 1/20 + 1/12 = 8/60
7/60 + 8/60 = 15/60 = 1/4
4 days * 2 = 8 days
The answer is (B).