00:01
So in this problem, there is no mention of compounding interest.
00:05
Therefore, we will use the simple interest formula, which is general formula is that the final amount or is equivalent to fee or the principal initial deposit multiplied by 1 plus the rape multiplied by fee.
00:23
The years or the number of clears elapsed.
00:28
So we are given the final amount and also the c.
00:40
So we are to find the rate of interest and the value of our p.
00:46
So let's rearrange this.
00:48
P is equivalent to a over 1 plus r c.
00:54
Okay.
00:55
So based on the first amount, in six years, the principal, will be equivalent to 10 ,400 and this one will be one plus what's the rate rate is our unknown p is six so this will be that given to six times r this is the first one okay and for the second um anario after eight years um the deposit or p will be equivalent to 11 ,200 so this is one plus number of years is eight and then you have r so let's um equate this two um equations because p it's just equivalent to p okay so let's equate this we write um 10 ,400 over 1 plus 6 r equivalent to 11 ,200 over 1 plus a a half okay so we are talking on this initial deposit here that's why we equate this two equations so we have one unknown here we have r so we can solve for this so what we will do is we will cross multiply okay so we have 10 ,400 multiplied by 1 plus 8 r we have 11 ,200 1 plus 6r so in this left side we have 10 ,400 plus 10 ,400 times 8 will be 8 to 3 ,200 r.
02:45
So we have 11 ,200 plus 11 ,200 times 6 is 67200r.
02:55
Okay, so let's transfer 10 ,400 to the right side later.
03:02
When we will transfer, it's 832.
03:10
Minus 67 200 11 ,200 minus 10 ,400 so forget to write our r ok, don't forget to write the r it is our unknown r minus this is also 67200 r now we subtract 67 ,200 from 83 ,200 we have 16 ,000 thousand are and 11 ,200 minus 10 ,400 is 800 right are therefore is equivalent to 800 over 16 ,000 we divide this we will have 0 .05...