The 7-digit numbers in a given area code have the form ABC-, where X, B, and C can be any digit 1-9 and A is restricted to 0-9. There are two other restrictions:
• B and C cannot both equal 1 since these values are designated for other purposes such as 911 (emergency)
and 411 (information), and
• 555-0100 through 555-0199 are reserved for fictional uses such as in television shows or movies.
According to these conditions, how many 7-digit numbers are possible in a single area
code?

The number of 7-digit numbers are possible in a single area code is 5248600

Step-by-step explanation:

The given parameters are;

The number of digits in the area code = 7

The possible digits for X, B and C are 1 - 9 = 9 digits

The number of possible digits for A is 0 - 9 = 10 digits

Exceptions

1) B and C cannot both =

2) 555-0100 through 555-0199 are reserved for television or movies

Therefore, we have, the number of 7 digits numbers without exceptions = 10×9⁶ = 5314410 numbers

The number of the exceptions are

Exception 1) 10 × 1 × 1 × 9 × 9 × 9 × 9 = 65610 numbers

Exception 2)  555-0100 through 555-0199 = 0199 - 0100 = 200 numbers

The number of possible numbers = 5314410 - 65610 - 200 = 5248600

The number of 7-digit numbers are possible in a single area code = 5248600.

7

step-by-step explanation:

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,