Arithmetic progression

[Ghujimhuji]

How does one find the value of m?

 

[Deleted member 4993]

How does one find the value of m?

View attachment 32310

Do you know the equation to calculate the sum of n terms in an arithmetic series?

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

READ BEFORE POSTING​

Please share your work/thoughts about this problem.

 

[Ghujimhuji]

Do you know the equation to calculate the sum of n terms in an arithmetic series?

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

READ BEFORE POSTING​

Please share your work/thoughts about this problem.

This is what I've got so far for the first part, im not sure where even to start to find m though

 

[Deleted member 4993]

View attachment 32314
This is what I've got so far for the first part, im not sure where even to start to find m though

Use the fact:

U_m = a +(m-1)*d