Question

Membership in a skiing club is expected to grow by about 8% per month. Currently,there are 530 members. In about how many months will membership reach 850 members?
A-14months
B-11months
C-9months
D-6months

Answer 1

Answer: D - 6 months

Step-by-step explanation:

It is given that,

The current number of members = 530,

Monthly rate of increasing members = 8 %,

Let after x months the number of members will 850,

Thus, we can write,

$530(1+\frac{8}{100})^x=850$

$530(1+0.08)^x=850$

$1.08^x=\frac{850}{530}$

$x log(1.08) = log(1.60377358)\implies x =\frac{log(1.60377358)}{log(1.08)}=6.13764228\approx 6$

Thus, About in 6 months the number of members will 850.

Answer 2

850 = 530 * (1.08)^x
850 / 530 = (1.08)^x
1.6 = (1.08)^x
x = 6

D, 6 months