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Study Material and Tips

### Tips to Solve Problems on Time and Distance

1. 2. x km/hr = 3. x m/sec = 4. If the ratio of the speeds of A and B is a:b , then the ratio of the times taken by them to cover the same distance is or b : a 5. Suppose a man covers a certain distance at x km/ hr and an equal distance at y km/hr . Then, the average speed during the whole journey iskm/hr....

### Tips to Solve Problems on Time and Work

1. If A can do a piece of work in n days, then A's 1 day's work = 2. If A’s 1 day's work =, then A can finish the work in n days. 3. A is thrice as good a workman as B, then: Ratio of work done by A and B = 3 : 1. Ratio of times taken by A and B to finish a work = 1 : 3. NOTE : Whole work...

### Tips to Solve Problems on Chain Rule

1. Direct Proportion: Two quantities are said to be directly proportional, if on the increase (or decrease) of the one, the other increases (or decreases) to the same extent. Ex. 1. Cost is directly proportional to the number of articles. (More Articles, More Cost) Ex. 2. Work done is directly proportional to the number of men working on it (More Men,...

### Tips to Solve Problems on Percentage

I.Concept of Percentage : By a certain percent , we mean that many hundredths. Thus x percent means x hundredths, written as x%. To express x% as a fraction : We have , x% = x/100. Thus, 20% = 20/100 = 1/5; 48% = 48/100 = 12/25, etc. To express a/b as a percent : We have, % . Thus, % = 25%; &am...

### Tips to Solve Problems on Decimal Fractions

I. Decimal Fractions : Fractions in which denominators are powers of 10 are known as decimal fractions. Thus ,1/10 = 1 tenth = .1; 1/100 = 1 hundredth = .01; 99/100 = 99 hundreths = .99; 7/1000 = 7 thousandths = .007,etc II. Conversion of a Decimal Into Vulgar Fraction : Put 1 in the denominator under the decimal point and annex with it as many zeros ...