Question

I have a total of Rs 300 in coins of denomination Rupees 1 ,rupees 2 and rupees 5 the number of Rs 2 coins is 3 times the number of rupees 5 coins. the total number of coins is 160 how many coins of each denominations are with me?

Answer 1

Here let us assume x,y, z for no of coins of Re 1, 2 and 5 respectively.

Then given information is

x+y+z = 160:

x+2y+5z = 300 and

y = 3z

Solving x+4z = 160 and x+11z =300

7z = 140,  z=20:   y = 60 and x = 160-y-z = 80

There are 80 coins of 1 Re,

                 60 coins of 2 Rs and

                 20 coins of 5 Rs.

Answer 2

Answer:

Total no. of coins = 160

The no. of 5 rs coins be x

The no. of 2 rs coins be 3x

The no. of 5 rs coins be 4x

The no. of coins => 1 coins 160 - ( 3x + x)

= 160 - 4x

Amount of 5 rs coins = 5x

Amount of 2 rs coins = 2x × 2 = 6x

Amount of 1 rs coin = 60 - 4x

.•. -> 5x + 6x + 160 - 4x = 300

-> 11x + 160 - 4x = 300

-> 7x + 160 - 4x + 160 = 300

-> 7x = 140

-> x = 140 / 7 = 20