GMATPrep Test 1 : PS #13

kaizenwerks,
in simple interest we are getting 600$ in 2 yrs so interest p.a = 200$
So kd/100 = 300 so k = 30000/d
Now we want to get 2400$ after 3 yrs. So we need to get 800$ p.a.
And let x is the principal amount.
So 300x/d = 800 => x = 8d/3.
IMO E

imo e as well,whats oa?

Guys I`m a little bit lose, what is the rules for simple interest?

kamitava, I can't understand at all what you said. Sorry. Could you please define it a little bit more. I know the formula (T=Prt), but I am SO confused...

in simple interest we are getting 600$ in 2 yrs so interest p.a = 200$

Yuri, I had a typo there! It should be

in simple interest we are getting 600$ in 2 yrs so interest p.a = 300$

The rest are fine! Sorry for my mistake! Are u able to get me now?

camitava,

could you explain further in detail:

in simple interest we are getting 600$ in 2 yrs so interest p.a = 300$

p.a is principal amount right? isn't the $300 the interest though? why are we dividing by 100?

So kd/100 = 300 so k = 30000/d
Now we want to get 2400$ after 3 yrs. So we need to get 800$ p.a.
And let x is the principal amount.
So 300x/d = 800 => x = 8d/3

8d/3 is the correct answer but i am still a bit confused. thanks.

thanks camitava! Got it!