12c i) ii) iii) help (2 Viewers)

[lolwot]

Can someone show me how they did these/your answers, I might of stuffed them up?

 

[Menomaths]

7 years?


(please someone say 'this' or 'i got that too')

 

[Menomaths]

87500 = n/6*(66,000-1500+1500n)

87500 = n/6*(64,500+1500n)

10750n+250n^2 = 87500

250n^2 + 10750N - 87500 = 0

n = -50 or n = 7

n =/= -50 therefore n = 7

 

[bedpotato]

7 years?


(please someone say 'this' or 'i got that too')

this

 

[NFmusic1995]

i did a stupid mistake, i found it normally, then time'd it by 3.... instead of divding, meh lost 1 mark since working is there LOL

 

[lolwot]

LOL I managed to find the first year one-third of her annual (not cumulative) salary equals $87500... 154 years. So like in the 154th year she saves exactly $87500 of her now $262500 salary. I blame the wording

but ii) is like 330796.93 ..right?