naveengupta

• Jun 26th, 2007

 

ans is 60 benches
 
let x=no of benches
     y=no of students per bench

given
 x*y=600,---------(1)

and given that 10 benches are less hence 2 students are seated more than per bench  then

600=(x-10)*(y+2)
600=xy+2x-10y-20------------(2)

since xy=600
then eq(2) is
2x-10y=20

2x-10(600/x)=20
 
on solving

we get x=60

sibarama

 Profile Answers by sibarama 

• Jun 19th, 2008

 

ans=60 Explanation:-Let no of benches=x
600/x=(600/(x-10))-2
equating This
we get
          2x^2-20x-6000=0
         =>x=60 or -50

hense x=60(no of benches)

SAUREEN ADANI

 Profile Answers by SAUREEN ADANI 

• Jun 10th, 2010

 

10*60=600
12*50=600
it means per bench 10 student requirs 60 benches.but 10 are less so that on 50 benches to accomodate 12 per bench. it means 2 more to be seated on each bench. so the answer is 60.

prititripathi

 Profile Answers by prititripathi 

• Feb 25th, 2011

 

given a*b=600

& (a-10)*(b+2)=600

ab-10b+2a-20=600

we knw ab=600

so 2a-10b=20

2a-10*600/a=20

solve quadratic eq. we get a=60 b=10