Help Please. I'm no good when it comes to math

question 5 is C

Question 4 is 37.68

Question 3 is 153.86 ft sq

The question about finding the area with a diameter of 16mm is 803.84

The next one is A. 25÷8

Step-by-step explanation:

C = 2 pi r

C = 2 pi (7.8) and you get 49.01

Becuse the question is asking to round c is the best choice

When using the formula of C = 2 pi r, since radius is half of the diameter, 12÷2=6

The formula for this one is A = pi r sq

You have the radius for this one is 7

Put 7 into that and you get. ~153.94

b.) 160 miles on a 5 gallons car

step-by-step explanation:

240/10=24 miles/gallon

160/5=32 miles/gallon

30/1=30 miles/gallon

168/6= 28 miles/gallon

32 miles/gallon is the most amount, so this is the best.

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1