Step-by-step explanation:
Since
varies directly as
we can write the relation as

where k is the constant of proportionality.
a) To solve for the k, we substitute the given values:


b) The equation relation x and y can be written as

c) When y = 9,

Answer: 68
Explanation:
Let x be the age of Mr Jasmi
y be the age of Miss Haslinda
a + b + c be the age of the 3 children
We can write:
(x + y + a + b + c)/5 = 38
But:
(a + b + c)/3 = 18
a + b + c = 18(3)
a + b + c = 54
Substitute this value to our first equation
(x + y + 54)/5 = 38
x + y + 54 = 38(5)
x + y + 54 = 190
x + y = 190 - 54
x + y = 136
Thus:
Mean age of (mr jasmi and miss Linda) = (x+y)/2
But x + y = 136
=> mean age = 136/2 = 68
25/20 × 100% = 125%
125% - 100% = 25%
25% profit :)
For this case we must resolve the following expression:
We have to:

The base change rule can be used if a and b are greater than 1 and are not equal to x.
We substitute the values in the base change formula, using 

Answer:
-4
Option A
Answer:
20% mark up
Step-by-step explanation:
[(48-40)/40]×100%= 20%