Answer:
Ivan got £90 more than Tanya.
Step-by-step explanation:
Ivan and Tanya share the amount £150 in the ratio of 4 : 1
Amount received by Ivan = 
= 
= £120
Similarly, amount received by Tanya = 
= £30
Difference in their amounts = 120 - 30
= £90
Therefore, Ivan got £90 more than Tanya.
I don't like trying all of them so I will make up my own which will probably be in the answers
so equation is
f(x)=pay
x=hours worked
solve so
f(1)=110
f(2)=130
f(3)=150
f(4)=170
they seem to be increasing in 20 increments so therefor the pay is linked to hours times 20 so that measn that every hour he works, he gets 20 dollars
therefor the answer is f(n+1)=f(n)+20 since we know that 1 hour=$20 so n+1hour=n+$20
the answe ris f(n+1)=f(n)+20