if length of a rectangle is incr by 20% and width is decr by
20% then area

Answer Posted / zammil

we know,
area=b*h
b gets increased by 20% i.e (b+0.20b)
h gets decreased by 20% i.e (h-0.20h)

rewriting the equation(area=b*h),

area=(b+0.20b)*(h-0.20h)
area=b(1+0.20)*h(1-0.20)
area=b(1.20)*h(0.80)
area=b*h*(1.20)*(0.80)
area=b*h*(0.96)

i.e new area=0.96 times the original area
if 100% was the original area,it has decreased to 96%
so,100%-96%= 4%

Is This Answer Correct ?    38 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

If a man can swim downstream at 6kmph and upstream at 2kmph, his speed in still water is: It takes 30 days to fill a laboratory dish with bacteria. If the size of the bactiria doubles each day, how long did it take for the bactiria to fill one half of dish?

938


if the sum of five consecutive nos. 35? how many prime numbers are there :

739


4 cows are there at the four corners of a square. if the radius of the rope is 1 and lenth of one side of the square is 14, find the area along the square which the cow cannot gaze.

825


If the total distance of a journey is 120 km .If one goes by 60 kmph and comes back at 40kmph what is the average speed during the journey?

709


If a bat costs Rs.30 in the year 1999 and Rs.250 in the year 2000.What is the percent increase in price?

803






Radha,Geeta&Revathi went for a picnic.After a few days they forgot the date,day and month on which they went to picnic.Radha said that it was on Thursday,May 8 and Geeta said that it was Thursday May 10.Revathi said Friday Jun 8.Now one of them told all things wrongly,others one thing wrong and the last two things wrongly.If April 1st is tuesday what is the right day,date and month? thought that he should not waste his time and started moving towards his residence at the speed of 3mi/hr.On the way,he gets the coach and reaches home at 6 o'clock.How far is his residence from railway station.

883


chief : tribe :: governor :

775


A person has Rs 100/- in his pocket, he can as 25 pencils or 15books. He kept 15% of the money for travelling expenses and purchased 5 ncils.So how many books he can purchase with the remaining money.

807


X2 – (A-3)X +(A+3) = 0 for what value of A the sum of square of roots will be least ?

792


A cycled from P to Q at 10 kmph and returned at the rate of 9 kmph. B cycled both ways at 12 kmph. In the whole journey B took 10 minutes less than A. Find the distance between P and Q.

822


If there are 1024*1280 pixels on a screen and each pixel can have around 16 million colors Find the memory required for this?

976


I most like to work with? Most men act though?

1431


if f(x)=1/x**2 , then f(f(f(x)))

802


(998-1)(998-2)(998-3).....(998-n)= ? when n>1000

924


A fold density is 19 times greater than the water and for copper it is 9 times.At what ratio you can mix gold and copper to get 15 times denser than water.

790