3p=p(1+0.06)^t
3=1.06^t
Log(3)=t*log(1.06)
T=log(3)/log(1.06)
T==18.9 years
Postulate: given segment AC the point B belongs to this segment if and only if segment AB + segment BC = segment AC.
Then you can use a stick and call A and Cits edges, the mark an intermediate point, i.e. between A and C, on the segment and verify that you can measure each segment AB, BC and AC ant the postulate is satisfied.
The answer would be 93.887
10% of anything is one tenth. One tenth of 60 is 6 -or 60/10 = 6
<span>5% of anything is half of 10% 5/10 = 1/2. Half of 6 is 3 </span>
<span>Add 6 and 3 and you have 9, the total discount. </span>
<span>So 15% of $60 is $9. </span>