Answer:
422
Step-by-step explanation:
Large rectangle
A = 2(lw+wh+lh)
A = 2(7*10+10*5+7*5)
A = 310
Small rectangle
A = 136
Now the squares that connect both, 4*3
Since you have 1 on each rectangle, the total area for this is 24
add 310 + 136 and substract 24
It does not say simple or compound interest.
Simple interest is rarely used these days, so assume compound.
Use the standard formula:
future value = present value*(1+rate/n)^(nt)
n=number of times interest is compounded per year (=1)
t=number of years
Plugging values,
200=100(1.09)^t
1.09^t = 2
take log
t(log(1.09))=log 2
t=log(2)/log(1.09)=0.6931/0.08618=8.04 years.
