A certain amount is equally distributed among certain number of students.
Each would get ` 2 less if 10 students were more and each would get 6 more if 15 students were less. Find the number of students and the
amount distributed.
Answers
Answer:
X students and each can be given Y rupees.
Now,
Each would get rs. 2 less if 10 students were more => (X+10) students would get each (Y-2)
Amount= (X+10)*(Y-2)
Each would get rs. 6 more if 15 students were less=> (X-15) students would get each (Y+6)
Amount= (X-15)*(Y+6)
(X+10)*(Y-2)=(X-15)*(Y+6)
XY-2X+10Y-20=XY+6X-15Y-90
8X-25Y=70. eq1
Similarly
XY=(X+10)*(Y-2)
XY=XY-2X+10Y-20
2X-10Y=-20.
2X*4–10Y*4=-80 Eq2
Using eq1 and 2
X=40
Y=10
.
Solution : Let the number of students be x and amount given to each student
be ` y.
Total amount distributed is xy
From the first condition we get,
(x + 10) (y - 2) = xy
xy - 2x + 10y - 20 = xy
- 2x + 10y = 20
- x + 5y = 10 . . . (I)
From the 2nd condition we get,
(x - 15) (y + 6) = xy
xy + 6x - 15y - 90 = xy
6x - 15y = 90
2x - 5y = 30 . . . (II)
Adding equations (I) and (II)
- x + 5y = 10
2x - 5y = 30
x = 40
Substitute this value of x in equation (I)
- x + 5y = 10
- 40 + 5y = 10
5y = 50
y = 10
Total amount distributed is = xy = 40 ´ 10 = ` 400.
` 400 distributed equally among 40 students.