The missing value for
is 
Explanation:
It is given that the equation for the table is 
The table has 2 column with 5 rows.
Thus, we have,
x y
-2 10
-1 ---
0 2
1 -2
2 -6
We need to determine the value of y when 
The value of y can be determined by substituting
in the equation 
Thus, we have,

Multiplying the term within the bracket, we have,

Adding the terms, we have,

Thus, the value of y when
is 6.
Hence, the missing value for
is 
Speed = distance / time
30 = d / 2.5
30 * 2.5 = d
75 = d
40 = d / 1.875
40 * 1.875 = d
75 = d
50 = d / 1.5
50 * 1.5 = d
75 = d
60 = d / 1.25
60 * 1.25 = d
75 = d
24 = 75 / time
time = 75/24
time = 3.125 hours
1. 28 x 3/4 = 21 kg
2. 1 hr = 60 mins
=》 1/4 hr = 60/4 = 15mins