23.6k views
3 votes
For the Rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. For an 10 month period, the last term is__ and the series sum is__ . For a 15 month period, the last term is __ and the series sum is . For a 20 month period, the last term is__ and the series sum is__ .

2 Answers

4 votes

Answer:For the Rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. For an 10 month period, the last term is__ and the series sum is__ . For a 15 month period, the last term is __ and the series sum is . For a 20 month period, the last term is__ and the series sum is__ .

Explanation:

User Rejeev Divakaran
by
7.7k points
6 votes

Answer:

1) For an 10 month period, the last term is 10 and the series sum is 55.

2) For a 15 month period, the last term is 15 and the series sum is 120.

3) For a 20 month period, the last term is 20 and the series sum is 210.

Explanation:

Given : For the Rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78.

To find :

1) For an 10 month period, the last term is__ and the series sum is__ .

2) For a 15 month period, the last term is __ and the series sum is .

3) For a 20 month period, the last term is__ and the series sum is__ .

Solution :

For the Rule of 78, for a 12 month period, the last term in the sequence is 12 and the series sums to 78. It is also defined as,

1+2+3+4+5+6+7+8+9+10+11+12=78

It is an AP with first term 1 and common difference 1.

The formula for sum of n terms is,


S_n=(n)/(2)[a+l]

Where, a is the first term and l is the last term

1) For an 10 month period, the last term is__ and the series sum is__ .

For an 10 month period, the last term is 10.


S_(10)=(10)/(2)[1+10]


S_(10)=5[11]


S_(10)=55

2) For a 15 month period, the last term is __ and the series sum is .

For an 15 month period, the last term is 15.


S_(15)=(15)/(2)[1+15]


S_(15)=7.5[16]


S_(15)=120

3) For a 20 month period, the last term is__ and the series sum is__ .

For an 20 month period, the last term is 20.


S_(20)=(20)/(2)[1+20]


S_(20)=10[21]


S_(20)=210

User Tal Bereznitskey
by
8.5k points