The number that you are thinking of is 4. To get this answer I did the opposite of how you received your answer.
40 - 12 = 28
28 ÷ 4 = 7
The number that you are thinking of is 4.
Hope this helps. <3 (sorry if it’s a little blurry)
Answer:
31 years to triple the investment
Step-by-step explanation:
Initial investment = 300
Triple amount that is final amount = 300*3= 900
rate of interest = 3.5 % = 0.035
we need to find out number of years (t)
for compounded continuously we use formula

A is the final amount
P is the initial amount
r is the rate of interest
t is the number of years

Divide both sides by 300

take 'ln' on both sides

ln(3) = 0.035t ln(e)
ln(e)= 1

t= 31.3889
Round to nearest whole number
t= 31 years