I have a total of 300 in coins of denomination 1, 2 and 5.The number of 2 coins is three times the number of 5 coins. The total number of coins is 160. How many coins of each denomination are with meh?
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Answered by
8
let the no. of rs 5 coins be x
& the no. of rs 1 coin be y
& no. of rs 2 coins be 3 x
a.q.t total no. of coins = 160
x + 3x+y = 160
4x + y = 160 eq. 1
again a.q.t 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
Answered by
0
Let the number of ₹5 coins be x.
Then,
number ₹2 coins = 3x
and, number of ₹1 coins = (160 – 4x) Now,
Value of ₹5 coins = x × 5 = 5x
Value of ₹2 coins = 3x × 2 = 6x
Value of ₹1 coins = (160 – 4x) × 1 = (160 – 4x)
According to the question,
5x + 6x + (160 – 4x) = 300
⇒ 11x + 160 – 4x = 300
⇒ 7x = 140
⇒ x = 140/7
⇒ x = 20
Number of ₹5 coins = x = 20
Number of ₹2 coins = 3x = 60
Number of ₹1 coins = (160 – 4x) = 160 – 80 = 80
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