Answer: C 2.5%
Step-by-step explanation:
The "Rule of 72" is a easy way to calculate how much time an investment will take to double with a given fixed annual rate of interest.
Just we have to divide 72 by the annual rate of return(r), we can get a rough estimate of how many years it will take to double the initial investment .
Now, in given problem: Let 'r' be the rate of interest
Time to double the amount=29 years
Thus by rule 72 ,
Therefore, C is the right option.
The second one is correct
Answer:
3 = 95, 4 = 85, if a and b are parallel
Step-by-step explanation:
Solution :
Let A = Economics, B = Mathematics
n(A) = 311, n(B) = 243, 
a). So, 
= 311 + 243 - 135
= 419
b). n(A only) = 311 - 135
= 176
n(B only) = 243 - 135
= 108
Exactly one of these two courses
= 0.568
c). Neither economics nor mathematics
= 0.162
Answer:
7 more students need to sign up.
Step-by-step explanation:
if you subtract the number of students needed by the number of students you have, you get 7 (30-23)
