Monday, March 9, 2009

PREP FOR GAMT : PERCENTAGES

CAT , GMAT , GRE , MBA
You should have clear idea on Percents before taking GMAT.

The word 'percent' means 'per hundred' or 'out of 100' and we use '%' to denote percent.

Inorder to workout the GMAT problems you must be aware of converting the percents to frations and decimals and vice versa.

Percent can be expressed as a fraction (with a denominator of 100) or a decimal.
For example, 69% = 69/100 = 0.69

To convert a percent to a fraction,divide the number by 100. You can also express the fractions in lowest terms.
For example, 80% = 80/100 = 4/5
To convert a fraction to a percent, multiply the number by 100.
For example, 2/5 = (200/5)% = 40%

To convert a percent to a decimal, divide the number by 100 (i.e., move the decimal point two places to the left, insert zeros to the left if necesssary).
For example, 2% =2/100 = 0.02
To convert a decimal to a percent, multiply the decimal by 100 (i.e., move the decimal point two places to the right)
For example, 0.32 =32/100=32%

HINTS FOR SOLVING GMAT PROBLEMS:

• If the order of increase or decrease is changed, THE RESULT IS UNAFFECTED
• if the value of a number is first increased by x% and then decreased by y%, then there is (x-y-(xy/100))% increase if positive , and decrease if negative

Price of sugar is increased . How much percent must a house hold must reduce his consumption of sugar so as not to increase his expenditure?
SHORT CUT : % REDUCTION= (INCREASE/100+INCREASE)* 100

Certain family have fixed budget for ice cream purchase for year . but,Ice cream price decreased by 20% due to winter season. find by how much % a consumer must increase his consumpion of ice creame so as not to decrease his expenditure.
SHORT CUT : %INCREASE IN CONSUMPTION = (REDUCTION/ 100- REDUCTION) *100

Water tax is increased by A% and consumption also increased by B% find what is the net effect in change?
SHORT CUT : [(A+B) + AB]/100