Phone numbers consist of a three-digit area code followed by seven digits. If the area code must have a 0 or1 for the second digit, and neither the area code nor the seven-digit number can start with 0 or 1, how many different phone numbers are possible?

1.28 * 10^10

Step-by-step explanation:

Area Code:  8 * 2 * 10

7 digit number: 8 * 10 * 10 * 10 * 10 * 10 * 10

The total number of area codes is 160

8,000,000 * Area Codes

1.28*10^10

maximum area = xy = (16)(32) = 512 ft2

to maximize the area of the garden, the side of the fence parallel to the side of the house should be 32 ft long, and the other two sides should both have length 16 ft.'

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