Please show how they got the number 0.008333

This is the solution:

6. Jonathan Letters has just inherited $10,000 and has decided to invest the money towards his long-term goal of wealth accumulation. Also, he was inspired by the concept of "pay yourself first" that he learned recently. He intends to put 10% of his salary at the end of each month into this investment plan. He is currently earning $36,000 annually, but expects his salary will increase at the rate of 0.5% per month. His financial advisor recommended a mutual fund with an expected rate of return of 10% p.a. Assume monthly compounding: (a) What is the effective annual rate (EAR) of the mutual fund? (b) How much money will he have after 10 years? (c) Will he achieve his goal of $1 million after 15 years? (d) If he wants to have $2 million after 25 years, how much must he invest per month? a) EAR =(1+12.10)121=10.47% b) FV10=(100001.104710)+FVCGA0.83338,120=(100001.104710)+{123600[0.0083330.005(1+0.008333)120(1+0.005)120]}=27,067+[300(266.2934)]=$106,955 c) No, he will not achieve his goal in 15 years. FV15=100001.104715+{123600[0.0083330.005(1+0.008333)180(1+0.005)180]}=44,531+179,984=224,515