A company buys equal numbers of two different card forms. It utilizes 2/3 of one kind and 9/10 of the other. What fraction of the total number is unused?

13/60

Step-by-step explanation:

Firstly, to solve this problem, we assign a value for the number of card forms bought. Let's say the company buys 30 of each kind, making a total of 60.

Now, we are made to understand that it utilizes 2/3 of one kind. This is equivalent to 2/3 * 30 = 20 and also 9/10 of another kind, making 9/10 * 30 = 27

Now, we need to know the fraction unused. In the first kind, amount unused is 30 - 20 = 10. In the second set, the fraction unused is 30 - 27 = 3

Total number unused is thus 10 + 3 = 13

The fraction of total unused is thus 13 / (30+30) = 13/60