on your birthday you receive a pda for $300. the value of the pda decreases by 20% each year. Whatt will its value be 4 years from now?
This can function like a simple interest problem because there's a principal ($300), a rate (20% decrease or -0.2 as a decimal each year), and a time (4 years). I = Principal x rate x time = (300)(-0.2)(4) = -240 In 4 years, the PDA loses $240 worth of value. So it has a $60 value now (300 - 240). NOW, that's assuming that the percent decrease is based on the $300 every year. If the percent decrease is based on the value each year, then it's different.
cool thanks:)
wait im guessing the percent decreases each year based on the value cause it says "decreases by 20% each year"
Yeah, see that becomes a question of whether you lose the same amount of money each year or different. I did it where it was the same each year. I'll do one for different: Do the simple interest function for the 1 year. I = 300 (-.2)(1) = -60 In the first year, the pda loses 60 of value, so its at 240 now. That becomes your new principal. Do it for another year. I = 240 (-.2)(1) = -48 In the second year, the pda loses 48 of value, so its at 192 now. That becomes your new principal. Do it for another year. I = 192 (-.2)(1) = -38.40 In the third year, the pda loses 38.40 of value, so its at 153.60 now. That becomes your new principal. Do it for the fourth year. This is the last one. I = 153.60(-.2)(1) = 30.72 In the fourth year, the pda loses 30.72 of value, so its at $122.88 after four years.
yeah i got $122.88 but idk which answer is correct
Well, I'd imagine that the second one would be the way to go because values of things of one year are not the same as they are for other years. Personally, I think the question is not worded well enough to where neither answer can be considered incorrect. I'd talk to your teacher and see what he/she wants.
yeah I hate it when questions are worded badly it just confuses people who are already having trouble with math
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