The probability of not picking a purple marble out of a bag of marbles is 2/5, if 2 purple marbles are taken out of the bag, reducing the number of purple marbles to 4, what will the new probability of picking a purple marble be?

Even if tossing around a few numbers often yields the "correct answer", the statements must be mathematically correct and logically sound

look at your statement:
3/5 = 2+4 , now that is news to me, I always thought 2+4 is 6 and not 3/5
Do you see what I mean ?
.....................

If prob of NOT picking a purple is 2/5
then prob of picking a purple is 3/5

We know that originally there were 6 purples, it was given.
let the total number of marbles be x

so we know that 6/x = 3/5
3x = 30
x = 10

so at the start, there 10 marbles, of which 6 were purple
after the take-out, there are 8 left of which 4 are purple
so new prob = 4/8 = 1/2

3/5 chance beofre of picking a purple marble

3/5 = 2+ 4

the rest of marbles = 4
so 4 / 4+4 = 1/2

To find the new probability of picking a purple marble, we need to determine the new total number of marbles and the new number of purple marbles.

We are given that the original probability of not picking a purple marble is 2/5, which means the probability of picking a purple marble is 1 - 2/5, or 3/5.

Let's assume the original total number of marbles is denoted by 'T' and the original number of purple marbles is denoted by 'P'. Therefore, initially, P/T = 3/5.

We also know that two purple marbles are taken out of the bag, reducing the number of purple marbles to 4. So now, the number of purple marbles is P - 2 = 4.

We want to find the new probability of picking a purple marble, denoted as P'/T' (where P' is the new number of purple marbles and T' is the new total number of marbles).

The new probability can be calculated as:
P'/T' = (P - 2) / T

Since we don't have the exact value of T, we cannot calculate the new probability without this information.

To find the new probability of picking a purple marble, we need to know the total number of marbles in the bag, as well as the number of purple marbles remaining after 2 have been taken out.

Let's denote:
N = Total number of marbles in the bag
P = Number of purple marbles in the bag

According to the information given, the probability of not picking a purple marble is 2/5. This means that the probability of picking a purple marble is 1 - 2/5 = 3/5.

We are also told that after removing 2 purple marbles, the number of purple marbles remaining is 4. So, P - 2 = 4, which implies P = 6.

Now we can calculate the new probability of picking a purple marble using the revised number of purple marbles (P = 6) and the total number of marbles (N):
New probability of picking a purple marble = P/N = 6/N

Please provide the total number of marbles (N) to calculate the new probability accurately.