Deveshi has a total of Rs. 590 as currency notes, in the denominations of Rs. 50, Rs. 20 and Rs.
10. The ratio of the number of Rs. 50 notes and Rs. 20 notes is 3:5. If she has a total of 25 notes,
how many notes of each denomination she has?
Let the number of Rs 50 notes and Rs 20 notes be 3x and 5x, respectively.
But she has 25 notes in total.
Therefore, the number of Rs 10 notes = 25 – (3x + 5x) = 25 – 8x
The amount she has
from Rs 50 notes : 3x × 50 = Rs 150x
from Rs 20 notes : 5x × 20 = Rs 100x
from Rs 10 notes : (25 – 8x) × 10 = Rs (250 – 80x)
Hence the total money she has =150x + 100x + (250 – 80x) = Rs (170x + 250)
But she has Rs 590. Therefore, 170x + 250 = 590
or 170x = 590 – 250 = 340
or x =
340
170
= 2
The number of Rs 50 notes she has = 3x
= 3 × 2 = 6
The number of Rs 20 notes she has = 5x = 5 × 2 = 10
The number of Rs 10 notes she has = 25 – 8x
= 25 – (8 × 2) = 25 – 16 = 9