A child learning to save money invested a capital of $ 250 at a nominal rate of 0

Note: we can assume an year consists of either 360 days or 365 days.

First, let us assume year, consists of 360 days.

simple interest on an investment = amount invested * nominal rate * number of days invested / 360 days.

here,

interest, amount invested, nominal rate are given, number of days invested shall be known.

=>$11.98 = $250 * 0.0825 *number of days / 360

=>11.98 = 20.625 * number of days /360

=>0.58084848 = number of days / 360

=>209.105453 = number of days.

=>209 days approximately.

if 360 days are assumed in an year the term of the deposit is for 209 days.

Alternate solution, if we assume year consists of 365 days:

interest = amount invested * nominal rate * number of days /365

=>$11.98 = 250 * 0.0825 * number of days /365

=>$11.98 = 20.625 * number of days /365

=>0.58084848 = number of days /365

=>number of days = 212 days.

IF 365 days are assumed in a year the term of investment is 212 days.