Hello there,
To start it off, 2 x 39= 78
So a is correct that would be 2 x 30+9 = 2x39= 78
So b is correct as well. 2 x 40-1= 2 x 39= 78
c is questionable 2 x 30 +9= 60 + 9 = 69
So d is correct 18 + 60 = 78
So e is correct 100-22 = 78
So 2 x 39 is not equal to (2 x 30) +9
Hope this helped!
Answer:

Step-by-step explanation:
Given: 60% of the boys play baseball and 24% of the boys play baseball and football in Seaton Park School
To find: percentage of those that play baseball also play football
Solution:
Let B denotes boys who play baseball and F denotes boys who play football.


Percentage of those that play baseball also play football = 
Simply convert first feets into miles
Given is 5280 feets=1 miles
63756 /5280=12.075 miles
70 minutes = 1.16666= 1.17 hrs
rate is 12.075 miles/1.17 hrs
Answer: OPTION D.
Step-by-step explanation:
For this exercise it is important to remember the following Trigonometric Functions:

Knowing this, we can identify that:

Therefore, the ratio
is equivalent to this Trignometric function:

127/2.54 = 50 inches which equals 4.16 ft