# Factorials

Q) If N = 1! – 2! + 3! – 4! +…..+ 23! – 24! + 25!, then what is the unit digit of N2524?
(a) 9
(b) 1
(c) 7
(d) 0

Each of the 150 residents of TG colony can be classified as having either a pet dog or pet cat, as vegetarian or as non-vegetarian, as living on first floor or ground floor.
It is further known that
1. The number of non-vegetarian residents is half the number of vegetarians.
2. The number of residents who live on ground floor is twice the number of residents who live on first floor.
3. The number of vegetarians having dog is same as the number of first floor residents having a pet dog.
4. The number of residents living on first floor having a non-vegetarian diet and pet cat, is one more than the number of residents living on ground floor who are vegetarian and have a pet dog.
5. The number of residents with a pet cat is 54 more than those with pet dog.

A toy company is planning to expand its operations by buying a new machine. They have short-listed two machines, A & B, based on the quality parameters, maintenance requirement, ease of operations etc. The production cost for each of these machines, for different production ranges is as shown in the table below. Answer the questions based on the data given. (All Costs are in Rs.)

In recent years, CAT DI questions have moved away from the traditional graphical representation to the tabular one. Furthermore, the concepts involved are usually very basic and typical. Below is one such example, based on simple concept, testing your ability to interpret the given data.

In township TG Town, a bus operator Veeta Volvos is planning to launch operations. They did some preliminary survey on the number of people availing bus services during any given 4-hour window of the day (provided in the table). Each Veeta Volvos bus needs one driver and can accommodate a maximum of 45 passengers at a time.

No no….don’t get it wrong.
Here, we are talking about one of the interesting topics in CAT-preparation (and all others MBA entrance tests also) i.e. Circular motion – a small but very important part of a broader topic: Time, Speed and Distance.
We are specifically focusing here on the meetings of the runners on a circular track (or any closed track for that matter). As we go on, I will post some questions and in the explanation I’ll discuss few important concepts that’ll remain with you at the end of this session.