Answer:
*2520
Step-by-step explanation:
A quarter of him income was spent on food
X (representing his income) - x/4= 3x/4
Then 2/3 was spent on house rent. Notice the, the question didnt say 2/3 of his income. Therefore it would be 2/3 of what is remaining after he pays for food.
2/3 * 3x/4= x/2
3x/4-x/2=x/4.
The remaining after all expenses are paid is 630. So:
x/4=630
x=630*4
x=2520
I think it’s a reciprocal function
Sum of the terms of the series is
Sn = n/2 ( a1+an )
we have n= 6 , a1= 17, an = 57
so Sn = 6/2 ( 17+57) = 3(74) = 222