If heater D is used on the third day, heater B has to be used on the fourth day and A has to be used on the second day. But if A is used on second day, then either B or C has to be used on the first day. But if heater B is used on the first day, then according to the question, the requirement of having different heaters on the first day and fourth days would not be fulfilled. Hence the heater that would be used on the first day is C.

1. Answer (b) Santosh , Ujjwal and Varun must each receive at least three pieces, but Tarun must receive at least four pieces. The maximum number of pieces that any person may receive is six ( 6 + 3+ 3+3 = 15 ), and only Tarun may receive six pieces. Ujjwal and Varun each may receive as many as five pieces, while Santosh may receive only four pieces at maximum.At least one pear.   2. Answer (c) Varun may receive no more than five pieces and Tarun may receive no fewer than four pieces. As a result, if Varun receives more pieces than Tarun, then Varun must receive five pieces, and Tarun must receive four pieces. Thus, statement (a) must be true. Since Varun will receive five pieces, none of the other three friends will receive any apple, accordingly, each of the other three friends must receive at least one orange and at least one pear. Thus, statement (b) and (d) must be true.

Answer: C) two Explanation: Clearly, we may mark such sets of 3 numbers, in which the middle number is 8 and each of the two numbers on both sides of it is a factor of 8, as shown below : 2 8 3 8 2 4 8 2 4 8 6 8 2 8 2 4 8 3 8 2 8 6 So, there are two such 8's. Hence the answer is C.

1. Answer (c) Each time we order 1, one apple is added to the basket but each time when 4 is ordered, one apple is removed from it. Required number of apples = number of 1's - number of 4's = 6 - 4 = 2 2. Answer (d) Each time we order 1, 2 or 3, one fruit is added to the basket but when ever we order 4, two fruits are removed from it. Required number = Number of 1's + Number of 2's + Number of 3's - 2 x (Number of 4's) = 6 + 6 + 7 - (2x4) = 19 - 8 = 11.

Answer: A) Both a and b follows Explanation: The police ought to find out the lackenings in existing security arrangements and make up for these inadequacies to strengthen security and thus prevent criminal activities in the forthcoming festival. So, both a and b follow. Arresting the known criminals does not ensure safety, for a novice can also indulge in crime. So, c does not follow.

Answer: B) 315 Explanation: Parallelograms are formed when any two pairs of parallel lines (where each pair is not parallel to the other pair) intersect.   Hence, the given problem can be considered as selecting pairs of lines from the given 2 sets of parallel lines.   Therefore, the total number of parallelograms formed = 7C2 x 6C2 = 315

Answer: C) 11 Explanation: Let the number of sides be n.  The number of diagonals is given by nC2 - n   Therefore, nC2 - n = 44, n>0  nC2 - n = 44 n2 - 3n - 88 = 0  n2 -11n + 8n - 88 = 0   n(n - 11) + 8(n - 11) = 0  n = -8 or n = 11.   As n>0, n will not be -8. Therefore, n=11.

Answer: A) 105 Explanation: Choose 1 person for the single room & from the remaining choose 2 for the double room & from the remaining choose 4 people for the four person room,   Then, 7C1 x 6C2 x 4C4  = 7 x 15 x 1 = 105