Answer:
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
