Answer:
1.8571428 hours
Step-by-step explanation:
Given that :
Price of stock A at 9 am = $12.53
Rate of increase = $0.12 per hour
Price of stock B at noon = $13.28
Rate of Decrease = $0.09 per hour
Let number of hours = x
Price of stock A at noon :12.53 + 0.12(3) = 12.89
12.89 + 0.12x = 13.28 - 0.09x
0.12x + 0.09x = 13.28 - 12.89
0.21x = 0.39
x = 0.39 / 0.21
x = 1.8571428
Hence the prices of the stock will be the at about 1.857 hours