Question

A man went to bank with rupees 1000. He asked the cashier to give him rupees 5 and 10 notes only in return. Write the linear equation in 2 variables. If number of 10 notes are 25, then find the number of 5 notes. Also represent it graphically

Answer 1

linear eq. is 5x+4y=1000
5x+4×25=1000
5x+100=1000
5x=900
x=180

Answer 2

Answer:

Let x represents the number of 5 rupees note and y represents the number of 10 rupees note,

Thus, the total amount = 5x + 10y

⇒ 5x + 10y = 1000 -----(1)

Which is the required linear equation in 2 variables.

Graphing equation (1) :

x-intercept = (200,0)

y-intercept = (0, 100)

So, we can plot equation on graph.

Now, number of 10 notes are 25,

⇒ y = 25.

⇒ 5x + 10×25 = 1000 ⇒ 5x = 1000 - 250 = 750

⇒ x = 150

Hence, the total number of 5 rupees note = 150.