Given :
Xanthe and Sarah together raised $302 .
If Xanthe raised $102 more than Sarah .
To Find :
The amount raised by Sarah .
Solution :
Let , amount raise by Sarah is x .
So , by the relation given , price raised by Xanthe is 102 + x .
Now , sum of their amount raised is :

Therefore , the amount raised by Sarah is $100 .
Hence , this is the required solution .
Here's a pattern to consider:
1+100=101
2+99=101
3+98=101
4+97=101
5+96=101
.....
This question relates to the discovery of Gauss, a mathematician. He found out that if you split 100 from 1-50 and 51-100, you could add them from each end to get a sum of 101. As there are 50 sets of addition, then the total is 50×101=5050
So, the sum of the first 100 positive integers is 5050.
Quick note
We can use a formula to find out the sum of an arithmetic series:

Where s is the sum of the series and n is the number of terms in the series. It works for the above problem.
Answer/Step-by-step explanation:
Recall: SOHCAHTOA
1. Reference angle = 70°
Adjacent side = x
Hypotenuse = 6 cm
Apply CAH. Thus,
Cos 70 = adj/hyp
Cos 70 = x/6
6 × cos 70 = x
2.05 = x
x = 2.05 cm
2. Reference angle = 45°
Adjacent side = x
Hypotenuse = 1.3 m
Applying CAH, we would have the following ratio:
Cos 45 = adj/hyp
Cos 45 = x/1.3
1.3 × cos 45 = x
0.92 = x
x = 0.92 m
3. The who diagram is not shown well. Some parts are missing, however you can still solve the problem just the same way we solved problem 1 and 2.