Math, asked by ndgibb84, 11 months ago

A girl has Rs 300 which consists of the denominations of rs 1 coins,rs 2 coins and rs 5 coins.The number of rs 2 coins is three times the number of rs 5 coins.The total sum of all the coins is 160.Find the number of each denominations.​

Answers

Answered by StarrySoul
4

Hello mate!✌

Let the no.of Rs.5 coin be x

No.of Rs.1 coin be y

No.of Rs.3 coin be 3x

Total no.of coins = 160

x + 3x + y = 160

4x + y = 160 eq.1

Total value of coins = 300

5x + 2(3x) + y = 300

11x + y = 300 eq.2

by elimination method

on subtracting both the equations

4x + y = 160

-11x - y = -300

-7x = -140

x = 20

on putting the the value of x in eq 2

4(20)+y = 160

80+y = 160

y = 160 -80

y = 80

now,

no of rs 2 coins = 3(20)

= 60

no. of rs 5 coins = 20

no. of rs 1 coins=80

Hope this helps

@adiba31☺❤


ndgibb84: can we find out using single variable?
StarrySoul: No
ndgibb84: tnx
Answered by singhalsmita
1

Answer:

Step-by-step explanation:

Let no. of Rs. 1 coins = x

and

No. of Rs. 5 coins = y

Given, no. of Rs. 2 coins = 3 times no. of rs. 5 coins

==> no. of Rs. 2 coins = 3y

Total money = Rs 300

==> 1*x + (2*3y) + (5*y) = 300     (rupees = denominations * total no of coins)

==> x + 6y + 5y = 300

==> x+11y = 300 ...........................equation 1

Also given, sum of coins = 160

==>x + 3y + y = 160

==> x+4y = 160..................................equation 2

Subtracting equation 1 and 2:

7y = 140

==>y=20 ....................no. of Rs. 5 coins

No. of Rs. 2 coins = 3y = 3*20 = 60

Therefore, No. of Rs. 1 coin = 160-(20+60) = 80

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