Answer:
The number of members the ski club have in total are:
Option: a
a. 67
Explanation:
A ski club planned a trip to Lake Tahoe, and 40 of the members signed up to go.
Now these 40 members constitute to the 60% population of the club.
Let x be the total number of members in the ski club.
This means that:

as number of members of the club can't be in decimals.
Hence, it is approximately equal to 67.
Hence, the number of members are: 67