Thirty percent of the members of a swim club have passed the

30% of the members have passed the test, thus 70% have not passed the test.

We also know that 30+12=42 members have not passed the test, thus 0.7*Total=42 --> Total=60.

Answer: A.
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Draw a table as below -



Now check 70% = 42 (12+30)

If 70% = 42
Then 100% = 42/70 *100 => 60

So there are 60 people in the wsimming club.
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The approach provided above can be used to solve this problem easily. however, i want to point out that this could also solved by using double sided set matrix method, similar to the problem which Bunuel explained at https://gmatclub.com/forum/of-30-applicants-for-a-job-14-had-at-least-4-years-144455.html#p1159040

Solution:

We are given that 30 percent of the members of the have passed the lifesaving test. If we use variable T for the total number of members, we can say:

0.3T = number of members who passed the test

Since we know that 0.3T is the number of members who passed the test, we can determine that 0.7T members did not pass the test. Next we are given that among the members who have not passed the test, 12 have taken the preparatory course and 30 have not taken the course. With this information we can set up the following equation:

12 + 30 = 0.7T

42 = 0.7T

420 = 7T

60 = T

Thus, there are 60 members in the swim club.

Answer is A.
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the idea is to recognize the two parameters at extreme....passed-not passed....prep course-no prep course...make a table with them...insert the values in tables...solution will be automatically in front of you.

We are given that 30 percent of the members of the have passed the lifesaving test. If we use variable T for the total number of members, we can say:

0.3T = number of members who passed the test

Since we know that 0.3T is the number of members who passed the test, we can determine that 0.7T members did not pass the test. Next we are given that among the members who have not passed the test, 12 have taken the preparatory course and 30 have not taken the course. With this information we can set up the following equation:

12 + 30 = 0.7T

42 = 0.7T

420 = 7T

60 = T

Thus, there are 60 members in the swim club.

Answer is A.
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Common Sense Ans: 30% have passed that means 70% is 30+12 = 42
Therefore, 42*30 = 1260, 1260/70 = 18 i.e 30 % = 18;
Therefore, 18+ 42 = 60 (30%+70%)
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Thirty percent of the members of a swim club have passed the lifesaving test. Among the members who have not passed the test, 12 have taken the preparatory course and 30 have not taken the course. How many members are there in the swim club?

(A) 60
(B) 80
(C) 100
(D) 120
(E) 140

Let total number of members be = X.
30% of X have passed the lifesaving test.
70% of X have failed the lifesaving test.
Out of those who failed the test 12 have taken the preparatory course and 30 have not taken the course.
Therefore 70% of X = 12 + 30 = 42
\(\frac{70}{100}\) * X = 42
X = 42 * \(\frac{100}{70}\) = 60
Answer A...

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let x is members of club
so
0.7*x = 12+30
0.7*x = 42
x = 60

Answer A

My approach to solve this question:
30% passed the test.
70% failed the test. 70% = 12+30= 42 members

therefore:
70% = 42
100% = x

70x= 42*100
x= 4200/70
x= 60
Therefore total members are 60.

Thirty percent of the members of a swim club have passed the lifesaving test. Among the members who have not passed the test, 12 have taken the preparatory course and 30 have not taken the course. How many members are there in the swim club?

(A) 60
(B) 80
(C) 100
(D) 120
(E) 140

Taking a moment to understand the situation can be helpful compared to diving straight in.

We have 30 percent of a club that have passed a course. This is a BINARY marker, since you are a members who has either passed or not. This means that the remaining 70 percent of equal 42 members (12+32).

70 percent = 42 members
10 percent = 6 members
100 percent = 60 members

(A) is your answer
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Great explanation thanks ScottTargetTestPrep, what happened to Thirty percent of the members of a swim club who have passed the lifesaving test? Are these not need to be taken into total members in the swim club or am I missing something here? Thanks

Let's break down the information given step by step to find the total number of members in the swim club.

Let's assume the total number of members in the swim club is 'x'.

Given:
30 percent of the members have passed the lifesaving test.
This means 70 percent of the members have not passed the test.

Among the members who have not passed the test:
12 have taken the preparatory course.
30 have not taken the course.

From this information, we can set up the following equation:
70% of x = 12 + 30

To solve for 'x', we first need to find 70% of x:
0.7 * x = 12 + 30
0.7 * x = 42

Dividing both sides of the equation by 0.7:
x = 42 / 0.7
x = 60

Therefore, the total number of members in the swim club is 60, which corresponds to option (A) in the given choices.