Answer:
4cm x 5cm x 3cm = 60cm
Step-by-step explanation:
You have to multiply each number by the next, then you have the area, to find the PERIMETER, you multiply each number by the amount of sides it is on and add
I can't see the whole question and which one do you need?
The expression for y in terms of "a" when value of x is doubled is 
<em><u>Solution:</u></em>
Given that,
y is directly proportional to 
Therefore,


Where "k" is the constant of proportionality
y = a for particular value of x
Therefore,
--------- eqn 1
We have to find when x is doubled
x is doubled means 2x
Let it be 
Hence we get,
--------- eqn 2
Substitute value of k from eqn 1, we get

Thus expression for y in terms of "a" when value of x is doubled is 
Answer:
$15.88
Step-by-step explanation:

$4.56 / 38 min
$0.12 / 1 min
76 - 69 = 7 minutes
7 x .12 = .84
16.72 - .84 = 15.88