How do scholars think the inca used the quipu?
a. as a writing system to record information about the ruler
b. as part of the costume of the priest when preforming rituals
c. as a weapon, similar to an axe, to enforce laws in the kingdom
d. as a record-keeping system to keep track of economic information.

The correct answer is:

D. as a record keeping system to keep track of economic information.

Explanation:

Quipus, also known as khipus or talking knots, were registering devices historically used in a number of cultures and particularly in the region of Andean South America. The cords included numeric and other values encoded by knots in a base ten positional system. The only potential Incan example of encoding and recording information could have been cryptic knotted strings identified as khipu.

the answer is b. 300t + 3/2xt