You are Here: Home >< Maths

# Extremely Confusing C2 MATHS Question watch

1. Wondering if anyone could help with this problem:

The sum of the first and third terms of a geometric series is 150. The sum of the second and fourth terms of the series is −75.
a) Find the first term and common ratio of the series.
b) Find the sum to infinity of the series.

This is from a C2 Solomon Paper and the mark scheme just confuses me.

Thanks
2. (Original post by lindseyyy)
Wondering if anyone could help with this problem:

The sum of the first and third terms of a geometric series is 150. The sum of the second and fourth terms of the series is −75.
a) Find the first term and common ratio of the series.
b) Find the sum to infinity of the series.

This is from a C2 Solomon Paper and the mark scheme just confuses me.

Thanks
So and
Can you see an easy way to link these two equations?
3. Hint, as this is geometric, think of multiplication or division.
4. (Original post by joostan)
So and
Can you see an easy way to link these two equations?
Thank you so much!
5. (Original post by lindseyyy)
Thank you so much!
No worries

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 12, 2013
Today on TSR

### The most controversial member on TSR?

Who do you think it is...

### Is confrontation required?

Discussions on TSR

• Latest
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE