Answer:
7.5 miles per hour.
Step-by-step explanation:
We have been given that Mr. Ward runs a lot. He ran 45 minutes each day, 5 days each week, for 16 weeks.
First of all, we will find time for that Mr. Ward ran in 16 weeks.
We will multiply 5 by 16 to find number of days for that Mr. Ward ran and then we will multiply the result by 45 minutes to find the time.


Now, we will divide 3600 minutes by 60 minutes to convert time into hours as:

Now, we will divide 450 miles by 60 hours to find Mr. Ward's average speed as:


Therefore, Mr. Ward's average speed in 7.5 miles per hour.
It is given that
a+b=20 -------------------- (1)
b+c=30 -----------------------(2)
We have to calculate
3 a + 4 b +7 c
Now multiplying equation(1 )by 3,we get
3 a+ 3 b=60 ----------------------------------(3)
and Multiplying equation( 2) by 4,we get
4 b + 4 c=120 -----------------------------------(4)
Adding expression (3) and (4),we get i.e left hand side of 3 to left hand side of 4 and right hand side of 3 to right hand side of 4.
3 a+ 3 b+ 4 b+ 4 c=60+120
Adding like terms, we get
3 a+ 7 b+ 4 c =180, Which is the required solution.
4(28) = 4(20) + 4(8)
The answer is 8
Because 28 is 20 and 8