Answer:
A- 480
Step-by-step explanation:
First, I'm going to work out 25% of 1200 for the before 1980 pennies.
10% = 120
20% = 240
5% = 60
240 + 60 = 300 pennies before 1980.
Next, work out 35% of 1200 instead.
20% = 240
+ 10%
30% = 360
+ 5% = 60
35% = 420 pennies from 1980-2000
Finally, work out how many pennies are leftover.
300 + 420 = 720
1200 - 720 = 480
A is the answer.
Hope this helps and have a good day!
