Question

In a box, three type of coins are present such as 20 paise,50 paise and 1 rupee , And a total of 27 coins are inside the box.If the total amount of money present in the box is 13 rupees then how many 50 paise coins are present in the box

Answer 1

Answer:

Step-by-step explanation:

let number of 50 paise coins be x

let number of 20 paise coins be y

let number of 100 paise (1 rupee) coins be z

now we have

   50x+20y+100z=1300 (13 rupee = 1300 paise) and x+y+z=27

⇒5x+2y+10z=130    

⇒2(x+y+z)+3x+8z=130

⇒2(27)+3x+8z=130

⇒3x+8z=76

⇒3x=76-8z

so 76 - a multipe of 8 must be a multiple of 3.

we can see this is satisfied by z=2 when 76-8z=60=3(20)

⇒x=20

⇒y=5

therefore the number of 50 paise coins are 20