Answer:
1,645 poles
Step-by-step explanation:
Here, we want to calculate the total number of poles
We can have an arithmetic progression here
Where the last term is the 58 piles , the first term is the top layer which is 12 and the common difference between the piles is 1
Firstly, we calculate the number of stacks which can be obtained using the nth term formula;
Tn = a + (n-1)d
58 = 12 + (n-1)1
58 = 12 + n - 1
58 = n + 11
n = 58-11
n = 47
So we have the stack high up to 47 units
So, using the sum of terms in an arithmetic sequence formula, we have;
Sn = n/2 ( a + L)
where a is the first term 12 and L is the last term 58
Thus, we have
Sn = 47/2( 12 + 58)
Sn = 47/2 * 70
Sn = 1,645
