Question

i have total of rupee 300 coins of demonstration rupee 1, rupee 2, rupee 5.the number of rupee 2 is three times the number of rupee 5 . total number of coin is 160. how many coins of each demonstration are with me .

Answer 1

Answer:

rs 1 - 80 coins

rs 2 - 60 coins

rs 3 - 20 coins

Step-by-step explanation:

let the no. of rs 5 coins = x

& the no. of rs 1 coin = y

& no. of rs 2 coins = 3 x

a.q.t total no. of coins = 160

x + 3x+y = 160

4x + y = 160 (eq. 1)

total rs = 300

5x + 2(3x) + 1y = 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 =80

now,

no of rs 2 coins = 3(20)  = 60

no. of rs 5 coins = 20

no. of rs 1 coins=80