Given:
Length of rectangle = (x+10) cm
Width of the rectangle = x cm
Perimeter = 32 cm
To find:
The length of the rectangle.
Solution:
We know that,
Where, l is length and w is width.
Substituting the values, we get
Subtract 20 from both sides.
Divide both sides by
So, the length is
Therefore, the length of the rectangle is 13 cm.
Answer:
Seth has 21 nickels
Step-by-step explanation:
Let n represent the number of nickels. Since Seth has 8 more nickels than dimes, then (n-8) is the number dimes.
Nickel is worth 5 cents and dime is worth 10 cents. Thus, n nickels are worth 5n cents and (n-8) dimes are worth 10(n-8) cents. The total value of Seth's coins is $2.35 that is 235 cents, then
Solve this equation:
First of all, note that all integers are either 0,1, or 2 modulo 3 (if you're not familiar with this terminology, it means that every integer is either a multiple of 3, or it is 1 or 2 away from a multiple of 3).
So, we can think of our numbers as
In order to make sure that the sum of any three adjacent numbers is divisible by 3, we have to make sure that any group of 3 three adjacent numbers contains a 0, a 1 and a 2. This is possible only if we arrange our 9 numbers in 3 groups of 3 numbers containing 0,1 and 2 exactly once, repeating always the same pattern.
For example, we could arrange our numbers following the pattern
or
We have possible patterns. Suppose for example that we choose the pattern
One possible way of following this pattern would be the arrangement
In fact, we substituted every '0' with a multiple of 3 (3, 6 or 9), every '1' with a number 1 away from a multiple of 3 (1, 4 or 7) and every '2' with a number 2 away from a multiple of 3 (2, 5 or 8).
This means that, once we fix a patter, we have 3 choices for the first 3 slots, 2 choices for the next 3 slots, and the final slot will be fixed. So, we have
possible ways of following a fixed pattern. Since the number of patterns was 6, we have
possible arrangements.