If a box B contains four marbles numbered 1 through 4. Then the number of ways of drawing marbles from B firstly three marbles and then remaining one marble is

The problem can be solved using the concept of combinations in probability.

Step 1: Identify the total number of marbles in the box. In this case, it is 4.

Step 2: Identify the number of marbles to be drawn in the first draw. In this case, it is 3.

Step 3: Use the combination formula to calculate the number of ways to draw 3 marbles from 4. The combination formula is C(n, r) = n! / [(n-r)! * r!], where n is the total number of items, r is the number of items to choose, and '!' denotes factorial.

So, C(4, 3) = 4! / [(4-3)! * 3!] = 4.

Step 4: Identify the number of marbles to be drawn in the second draw. In this case, it is 1 (the remaining marble).

Step 5: Since there is only one marble left, there is only one way to draw it.

So, the total number of ways of drawing marbles from box B firstly three marbles and then the remaining one marble is 4 * 1 = 4.