Let the number of notes of denomination1000 be 2x.
Therefore, the amount = ₹ 2000x
Let the number of notes of denomination 500 be 3x.
Therefore, the amount = ₹ 1500x
Let the number of notes of denomination100 be 5x
Therefore, the amount = ₹ 500x
Given: Total amount = ₹ 5,00,000
2000x+1500x+500x=₹ 5,00,000
4000x=5,00,000
x=5,00,0004,000=125
Therefore, the number of notes of denomination 1000
=2x=2×125
= 250 notes.