Answer:
3 : 7 =>
Anna = $180
Raman = $420
1 : 4 =>
Anna = $120
Raman = $480
Step-by-step explanation:
<u>Shares when ratio is 3 : 7</u>
Anna : Raman = 3 : 7
Sum of ratio 10
Anna's share=

Raman 's share=

<u>Shares when ratio is 1 : 4</u>
Anna : Raman = 1 : 4
Sum of ratio = 5
Anna 's share =

Raman's share =

ANSWER
or 
EXPLANATION
For 
We make y the subject to obtain,

We can easily graph this function, because we just have to transform the graph of
by shifting the intercept up to
.
As for the straight line,
,
We find the intercepts as follows,
When
.
When
.
We plot the points
and
.
We now draw the two graphs on the same graph sheet. The intersection of the two graphs gives the solution to be
or 
See graph
Percentage increase in the rate of all rail season tickets to London = 4%
Price of the rail ticket from Cambridge to London increased by = 121.60
Let us assume the price before the increase in the fare = x
Then
4% * x = 121.60 dollars
(4/100) * x = 121.60 dollars
x/25 = 121.60 dollars
x = 25 * 121.60 dollars
= 3040 dollars
So the price of the ticket from Cambridge to London before the increase in price was 3040. I hope the procedure is simple enough for you to understand.
Zenitsu from Demon Slayer
Example:
If I give u a ratio of the number of teachers to students is 2:1 would mean that for every 2 teachers there is 1 student.
In question 10(a) the ratio of grey to black is 3:1 which means that the percentage would be 33%
In 10 (B) the ratio would be 6:4