Nitin borrowed some money at the rate of 6% p.a

Nitin borrowed some money at the rate of 6% p.a. for the first three years,9% p.a. for the next five years and 13% p.a. for the period beyond eight years.If the total interest paid by him at the end of eleven years is Rs. 8160,how much money did he borrow ?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #39290