Question

3 bags and 4 pens together cost Rs 257 whereas 4 bags and 3 pens together cost Rs 324. Find the total cost of 1 bag and 10 pens.

Answer 1

Answer:

155

Step-by-step explanation:

bag = b

pen = p

3b + 4p = 257

4b + 3p = 324

3b + 4p + 4b + 3p  = 257 + 324

7b + 7p = 581

7(b+p) = 581

p + b = 581 / 7

p + b = 83

4b + 3p - (3b + 4p) = 324 - 257

b - p = 67

b - p + (b + p) = 67 + 83

2b = 150

b = 75

p = 83 - 75 = 8

b + 10p = 75 + 80 = 155  

Answer 2

$\Large{\textbf{\underline{\underline{According\;to\;the\;Question}}}}$

Assumption

Cost of a bag be ₹ p

Also,

Pen be ₹ t

So,

3p + 4t = 257 ………..… (1)

4p + 3t = 324 …...… (2)

Now,

Multiply (1) by 3 and (2) by 4,

9p + 12t = 770 ………..…(3)

16p + 12t = 1296 ………..…(4)

Now,

Subtracting (3) from (4),

7p = 525

p = 525/7

p = 75

Cost of a pen = ₹ 75

Substituting value of p in (1),

3p + 4t = 257

3 × 75 + 4t = 257

225 + 4t = 257

4t = 257 - 225

4t = 32

t = 32/4

t = 8

So,

Cost of pen = ₹ 8

Also,

Cost of 10 pens

= 8 × 10

= ₹ 80

Cost of 1 bag & 10 pens

= 75 + 80

= ₹ 155.

Therefore,

Total cost of 1 bag & 10 pens = ₹ 155