Question

13. A bag has a total of 120 notes in denominations of Rs.2, Rs.5 and Rs. 10. The total value of the notes in
the bag is Rs.760. If there were twice as many Rs.5 notes, the total value of the notes would be Rs.960.
Find the number of Rs.10 notes in the bag.​

Answer 1

Number of $Rs.10$ notes in bag is 40

Step-by-step explanation:

Total number of notes =120

total value of notes=760

let there are x number of rupees two notes and y number of 5 rupees note,z number of 10 rupees notes

$2x+5y+10z=760-(i)$

if there were twice as many rupees of rupees 5 notes=$2\times5y=10y\\2x+10y+10z=960-(ii)$

Now,subtracting equation (i) from (ii)

$5y=200\\y=40$

put $y=40$ in equation (i)

$2x+5(40)+10z=760\\2x+10z=760-200\\2x+10z=560-(iii)$

putting equation (iii) in equation (ii) we get

$560+10z=960\\10z=400\\z=40$

so,number of $Rs.10$ notes in bag is 40

Answer 2

Step-by-step explanation:

let x be number of ₹2 and y be number of ₹3 and z be number of ₹10.

given in the question

X+Y+Z= 120....(1)

and,

2X+5Y+10Z=760........(2)

If there were twice as many ₹5 notes means,

2X+5Y+10Z=960......(3)

Solving equations (2) and (3) we will get

Y= 40

Thus substituting in equation (2) we get

2X+(5×40)+10Z=760

2X+10Z=560......(4)

and from equation (1)

X+Z=80.......(5)

Equating equation (4) and (5) we get,

Z=50

therefore the number of ₹10 notes in the bag is 50