How many 7-digit telephone numbers can be formed if the first digit cannot be 0 or 1

8,000,000 combinations

Step-by-step explanation:

Since we have 10 digits per slot, we need to remove two digits, 0 and 1, for the first slot therefore we get:

8 × 10 × 10 × 10 × 10 × 10 × 10 =

8,000,000 combinations

4+n=5

step-by-step explanation:

this is because the four is four hours and the n represents the 1 extra hour over the weekend.

b= i'm srry i don't know that one.

4+n=5 n=1 because if vernon plays 5 hours a week then 4+1=5 hours.

hope this : )

7.25

step-by-step explanation:

we know that 7 equals to 7.0. we also know that 1/4=0.25. so we can add the two together and we get 7.25