Hi Kostyan - Ok here is my understanding of your solution. When you say let's monthly payment be x.

So A=P(1+r/100)^n ----------------------------------------------------------------(1)

A= 1000(1+0.1)^1 = 1100.

So Principle for 2nd month will be 1100-x -------------------------------------(Am I right over here?)

Again using the same formula as 1

A = (1100-x) (1+0.1)^1 = 1210-1.1x --------------->

How did you get 1210-2.21x?So Principle for the 3rd month will be 1210-1.1x-x = 1210-2.1x----------------------(Am I right over here?)

A = (1210-2.1x) (1+0.1)^1 = 1331 - 2.31x

Amount after the last payment should be Zero. Therefore,

1331 - 2.31x = 0 => 2.31x=1331 => x=

_________________

Best Regards,

E.

MGMAT 1 --> 530

MGMAT 2--> 640

MGMAT 3 ---> 610

GMAT ==> 730