Answer:
A
Step-by-step explanation:
The largest square piece will be the largest factor between 24 and 18. This means the largest number that divides into 24 and 18. This number is 6. So each piece will be 6 inches by 6 inches.
2(5*4)+2(4*3)+2(3*5)=94 sq.m (Orginial SA)
2(4*5)+2(5*6)+2(6*4)=148 sq.m (Total SA)
148-94=54 (New SA)
For any equation,

assume solution of a form, 
Which leads to,

Simplify to,

Then find solutions,

For non repeated real root y, we have a form of,

Following up,
For two non repeated complex roots
where,

and,
the general solution has a form of,

Or in this case,

Now we just refine and get,

Hope this helps.
r3t40
Answer:
576 ways
Step-by-step explanation:
There are 4 choices for the column of pawn in the 1st row
There are 3 choices for the column of pawn in the 2nd row,
There are 2 choices for the column of pawn in the 3rd row, and
There is 1 choice for the column of the pawn in the 4th row
Which gives a total of 4! = 24
Also, the pawns are distinct, so there are 4! ways to place them in these chosen positions;
4! = 24
So, there are 24 * 24 possible ways
= 576 ways
Answer:
Turtle = 11 m / min
Snail = 1 m / min
Total approach speed = 12 m/min
360 m / (12 m/min) = 30 min
Separation is 30 min at assumed speed of 1 m/min
But we know the separation is 40 min
So turtle moves at 3/4 * 11 m / min = 33 m/ 4 min
Snail moves at 3/4 * 1 m /min = 3/4 m / mi
Total approach speed = (33 + 3) / 4 = 9 m / min
So in 40 min
9 m / min * 40 min = 360 m
(Leaving out those units, they approach at 12 * unit of speed)
So the unit of speed has to be 360 m / 40 min = 9 m / min