Question

cost 10 pens and 5 pencils is 100 than find the cost of 8 pens and 4 pencils

Answer 1

Answer:

10x + 5y = 100

Here if x=5 and y= 10 then above equation will be satisfied

.

Now 8x + 4y = 8×5 + 4×10 = 80

Step-by-step explanation:

Answer 2

The 8 pens and 4 pencils cost is Rs.80

Given:

The cost of 10 pens and 5 pencils is Rs.100

To find:

8 pens and 4 pencils cost

Solution:

As we know that, from the given  

10 Pens + 5 Pencils = 100 ……… (1)

8 Pens + 4 Pencils = x ……… (2)

As divided by 5 for equation 1, we can get  

2 Pens + 1 Pencil = 20 ………. (3)

Multiply by 4 to the L.H.S of the above equation (3), results

We gets, 8 pens +4 pencil

So like as that, multiply by 4 to the R.H.S of the equation (3), then  

8 Pens+ 4 Pencil = $20 \times 4=80$

So, 8 pens and 4 pencils cost is Rs.80