Question

A pen cost Rs. 13 and notebook cost Rs. 17 .A school spend exactly Rs .10000 in the years 2017-18 to buy X pens and y note book such that X and y are close as possible ( i.e.,( x- y) is minimum) . Next year, in 2018-19, the school spend a little more than Rs .10000 and buy y pens and X note book. how much more did the school pay?​

Answer 1

Answer:

Step-by-step explanation:

given, 13x+17y=10000 ------------------1

           17x+13y=10000+L------------------2

where L is the little amount of money used in the year 2018-19

adding both the equations, we get

 x+y = (20000+L)/30

by substracting both the eqns

x-y = L/4

L =4(x-y) = 4a (say) ..a is minimum

therefore x+y = 20000+4a/30 = 666 + (10+2a)/15

for minimum value of a , a=10

here L = 4a = 4×10 = 40

∴the school paid 40 rupees extra