The banking team of jagranjosh.com has come up with concept and sample questions for Arithmetic. The concept provided by us will help you to understand the topic. The sample questions offered by us are framed by keeping in view need of the question paper.
In solving problems the following points will prove helpful:
(i) If a man can do a piece of work in 20 days, he will do 1/20 of the work in 1 day. Conversely, if a man can do 1/20 of a work in 1 day, he will finish the work in 20 days.
(ii) If the number of men engaged to do a piece of work is changed in the ratio 5 : 4, then time required for the work would change to the ratio 4 : 5.
(iii) If A is thrice as good as B, A will take 1/3 of the time that B takes to do a certain work.
TIME AND DISTANCE
If a man travels 5 km in each hour, his speed is said to be 5 Ian per hour. So the speed of the body is the rate at which it is moving, and is measured by the distance which the body would cover in a given time.
Speed X Time = Distance
Speed = Distance/Time
Time = Distance/Speed
The face of a clock or a watch is a circle which is divided into 60 minute spaces. The minutes hand passes over 60 minute spaces while the hours hand goes over 5 minute spaces. That is, in 60 minutes the minutes hand gains 55 minutes on the hour hand.
In every hour
(a) The hands coincide once.
(b) They are twice at right angles when the hands are 15 minutes spaces apart.
(c) They point in the opposite directions once when they are 30 minutes spaces apart. The hands are in the same straight line when they are coincident or opposite to each other.
Note: The minute hand (MH) is also called the long hand; and the hour hand (HH) the short hand.
Too fast, too slow
If a clock indicates 7.10 when the correct time is 7.00, it is said to be 10 min too fast. If it indicates 6.50, when the correct time is 7.00, it is said to be 10 min slow.
The following facts should be remembered about a calendar:
1. In an ordinary year there are 365 days, that is, 52 weeks + 1 day. Therefore, an ordinary year contains 1 odd day.
2. A leap year contains two odd days.
3. 100 years = 76 ordinary years + 24 leap years = a number of weeks + (76 + 2 x 24) days
= a number of weeks + 7 weeks + 5 days.
100 years contain 5 odd days
4. 200 years contain 3 odd days.
5. 300 years contain 1 odd day.
6. 400 years contain no odd day.
7. 1 January, AD 1, was Monday. Therefore, the days cannot be as below:
Sunday - 0, Monday - 1, Tuesday - 2, Wednesday - 3, and so on.
8. February has 29 days in a leap year.
9. The last day of a century cannot be a Tuesday, Thursday, or Saturday.