Answer:
B=45
Step-by-step explanation:
Multiply 8 by 5
Add 40 and 5 together
I think it is 60 years old?
Current amount in account
P=36948.61
Future value of this amount after n years at i=11% annual interest
F1=P(1+i)^n
=36948.61(1.11)^n
Future value of $3000 annual deposits after n years at i=11%
F2=A((1+i)^n-1)/i
=3000(1.11^n-1)/0.11
We'd like to have F1+F2=280000, so forming following equation:
F1+F2=280000
=>
36948.61(1.11)^n+3000(1.11^n-1)/0.11=280000
We can solve this by trial and error.
The rule of 72 tells us that money at 11% deposited will double in 72/11=6.5 years, approximately.
The initial amount of 36948.61 will become 4 times as much in 13 years, equal to approximately 147800 by then.
Meanwhile the 3000 a year for 13 years has a total of 39000. It will only grow about half as fast, namely doubling in about 13 years, or worth 78000.
Future value at 13 years = 147800+78000=225800.
That will take approximately 2 more years, or 225800*1.11^2=278000.
So our first guess is 15 years, and calculate the target amount
=36948.61(1.11)^15+3000(1.11^15-1)/0.11
=280000.01, right on.
So it takes 15.00 years to reach the goal of 280000 years.
First off we have x number of students in the robotics club, 12 more in the Science club, and 84 students in total. This means:
Robotics Club = x
Science Club = (x + 12)
Total = 84
Okay, so here's the equation:
x + (x + 12) = 84 ~ Add like terms.
2x + 12 = 84 ~ Subtract 12 by both sides.
2x = 72 ~ Divide both sides by 2.
x = 36 ~ Meaning that the Robotics Club has 36 members.
At this point you can do: 84 - 36 = 48 which gives you the number of members in the Science Club, though...:
36 + (36 + 12) = 84 ~ Add the two in the parenthesis to get your answer.
36 + 48 = 84 ~ 48 is the number of Students in the Science Club.
84 = 84
In conclusion: The Science Club has 48 students.
Hope that helps. ^ ^
{-Ghostgate-}
