At a certain rate of simple interesrt,a sum double itsef in 10 years.In how many years would it treble itsef?

• In 20 Years sum will be treble.
  
  let P be the sum, R be the rate.
  Therefore S.I = (P*R*10)/100 = PR/10
  So, PR/10+P = 2P (bcoz given)....(1)
  
  On solving (1) , We have
  
  R=10%
  
  Now,
  Let T be the time in which sum trebles itself.
  
  S.I = (P*10*T)/100 (here rate will be 10 bcoz we have find out it above)
  
  = PT/10
  
  Therefore PT/10+P = 3P
  So, T=20 Years
• 10 years agoHelpfull: Yes(33) No(11)
• I=PRT/100
  
  where I-intrest,R-rate of intrest,T-time,P-Principle amount
  
  now total amount A=P+I
  
  so, A-P=PRT/100
  
  money doubles itself in 10 years so A=2P and T=10
  
  => 2P-P=PRT/100
  => P=PRT/100
  =>100=RT
  =>R=10
  
  NOW Money tripled in x year A=3P then
  
  A-P=PRT/100
  =>3P-P=PRT/100
  =>2P=PRT/100
  =>200=RT
  =>T=20
  so 20years! :D :)
  
  
  so time for tripple the value is 18.....
• 10 years agoHelpfull: Yes(14) No(1)
• just put the short cut formula
  if it will be triple then use this formula (p-1)*100/n
  so p=3
  n=10
  so 20 years it would be triple.
  if it will double then just use this formula 100/n
• 10 years agoHelpfull: Yes(9) No(0)
• ans-15 years
  
  rate=((100/p)/(p*10))=10
  for 2 year rate is=10
  means for 1 Years it's =5
  so In 15 Years sum will be treble
• 10 years agoHelpfull: Yes(8) No(6)
• let Rate be R AND sum be X THEN,
  SI=(R*X*10)/100=X(SINCE TIME IS 10 YR AND SUM SOUBLES SO SI WILL BE X ONLY)
  FROM ABOVE WE GET R=10
  NOW SUM TREBLE ITSELF SO SI WILL BE 2X
  THEREFORE,
  2X=(10*X*T)/100 HERE T IS TIME
  WE GET T =20.
  
• 10 years agoHelpfull: Yes(2) No(0)
• sum doubles means take 100 it becomes 200 for 10 years
  take 100 it becomes 300 in how many years means
  diff 100 and 200 is 100 in 10years
  diff 100 and 300 is 200in 200*10/100
  so ans is 20
  
• 10 years agoHelpfull: Yes(1) No(0)
• after 10 years amount = 2p
  so, SI=2P-P = P
  P=(P*R*10)/100
  r=10%
  now amount = 3P
  SI= 3P-P=2P
  2P=(P*10*T)/100
  T=20years
• 10 years agoHelpfull: Yes(1) No(0)
• Consider rate of Interest R,Sum P and Time T,
  
  Sum doubles itself in 10 years,so
  P=(P*10*R)/100
  R=10
  
  Now,Sum trebles in Suppose T years,
  So,
  2P=(P*10*T)/100
  T=20 Years
• 10 years agoHelpfull: Yes(1) No(0)
• ans= 15 years
• 10 years agoHelpfull: Yes(0) No(3)
• assume interest rate is x%.any nd after y years it will be triplet.
  so 10(100+x)=200...so (100+x)=20...again for triplet y(100+x)=300.y=15.
  
  so ans will be15
• 10 years agoHelpfull: Yes(0) No(2)
• 20 Years
• 10 years agoHelpfull: Yes(0) No(0)
• 20 years
• 10 years agoHelpfull: Yes(0) No(0)
• by using shortcut method
  (n1-1)/t1 = (n2-1)/t2
  where
  n1=2
  t1=10
  n2=3
  t2=?
  (2-1)/10 = (3-1)/t2
  t2=20yrs
  
• 9 years agoHelpfull: Yes(0) No(1)
• for same rate , p*100/p*10 = 2*p*100/p*n
  here equalize two conditions because of same rate ,
  n= 20 will obtain by solving that equation.
  In 20 years it would be treble .
• 7 years agoHelpfull: Yes(0) No(0)