Answer:
68cm^2
Step-by-step explanation:
Well there's not much to explain - the problem statement does it for us.
The surface area is equal to the sum of areas of the walls. There's 2 l*w walls, 2 l*h walls and 2 h*w walls.
SA = 2*l*h + 2*l*w + 2*h*w
SA = 2*4cm*6cm + 2*4cm*1cm + 2*6cm*1cm = 48cm^2 + 8cm^2 + 12cm^2 = 68cm^2
Answer:
answer a because -15/8 is -1.875
The two numbers are 12 and 15
<em><u>Solution:</u></em>
Let the smaller number be "x"
Let the larger number be "y"
Given that,
<em><u>The sum of two numbers is 27</u></em>
Therefore, we frame a equation as:
Smaller number + Larger number = 27
x + y = 27 ------ eqn 1
<em><u>The larger number is 3 more than the smaller number</u></em>
Larger number = 3 + smaller number
y = 3 + x ------- eqn 2
<em><u>Let us solve eqn 1 and eqn 2</u></em>
<em><u>Substitute eqn 2 in eqn 1</u></em>
x + 3 + x = 27
2x + 3 = 27
2x = 27 - 3
2x = 24
<h3>x = 12</h3>
<em><u>Substitute x = 12 in eqn 2</u></em>
y = 3 + 12
<h3>y = 15</h3>
Thus the two numbers are 12 and 15
The number of cows is given by
So, after 
years, the number of cows will be
We want this number to be twice as much as the original:
First of all, we can cancel 14 from both sides:
Finally, on the right hand side, we can use the exponent rule
to get
To solve this equation, we must impose that the two exponents are the same:
And clearly this is true if and only if 
. So, it will take 5 years for the cow heard to double in number.
You can do the exact same steps to find the doubling time for the sheeps.
