A sum of Rs 800 is in the form of denominations of Rs 10 and Rs 20. If the total number of notes be 50. Find the number of notes of each type.
Let the number of notes of Rs 10 are 
Number of notes of Rs 20 are 
Amount due to Rs 10 notes = 
Amount due to Rs 20 notes = 
According to the question total amount = Rs 800
Therefore the number of notes of Rs 10 are 
Number of notes of Rs 20 are 
9