Olympiad workbookIOQMBasics of Mathematics
A pen costs ₹ 11 and a notebook costs ₹ 13 . Find the number of ways in which a person can spend exactly ₹ 1000 to buy pens and notebooks.
Correct answer
7
Step-by-step solution
Cost of a pen is ₹ 11 Cost of a notebook is ₹ 13 aligned & 11 x+13 y=1000 & y= 1000-11 x 13 I & 12-11 x 13 I (13-1)-(13 x-2 x) 13 I & 2 x-1 13 I 12 x-6 13 I & 13 x-(x+6) 13 I x+6 13 I & x=13 -6 (1 x 90) & x 7,20, , 85 = 1,2, , 3 aligned