12. A man has certain note of denomination 20 and 5 which amount to 38

1.	12. A man has certain note of denomination 20 and 5 which amount to 380. If the number of notesof each kind are interchanged,they amount to 60 less than before. Find the number of notes ofeach denomination
Answer» Let no. Of 20 notes be n and no. Of 5 notes be mThen 20n + 5m = 380.....(1)If no. Of notes interchangedThen 5n + 20m = 320.....(2) On solving given equations20m - 5/4m = 320-9575m = 225x4m = 3x4 = 12 Putting value of m in equation (1)20n + 60 = 38020n = 320n = 16 Number of 20 notes = 16Number of 5 notes = 12

12. A man has certain note of denomination 20 and 5 which amount to 380. If the number of notesof each kind are interchanged,they amount to 60 less than before. Find the number of notes ofeach denomination

Answer»

Let no. Of 20 notes be n and no. Of 5 notes be mThen 20n + 5m = 380.....(1)If no. Of notes interchangedThen 5n + 20m = 320.....(2)

On solving given equations20m - 5/4m = 320-9575m = 225x4m = 3x4 = 12

Putting value of m in equation (1)20n + 60 = 38020n = 320n = 16

Number of 20 notes = 16Number of 5 notes = 12