Question

SECTION II (Case Study)
17. Dipesh bought 3 notebooks and 2 pens for Rs 80. His friend Ramesh said that
price of each notebook could be Rs 25. Then three notebooks would cost Rs 75
the two pens would cost Rs 5 and each pen could be for Rs 2.50. Another friend
Amar felt that Rs 2.50 for one pen was too little. It should be at least Rs 16. Then
the price of each notebook would also be Rs 16. Lokesh also bought the same
types of notebooks and pens as Dipesh. He paid 110 for 4 notebooks and 3 pens
Let the cost of one notebook be x and that of pen be y. Which of the following
set describe the given problem?
(a) 2x + 3y = 80 and 3x + 4y = 110
(b) 3x + 2y = 80 and 4x + 3y = 110
(c) 2x + 3y = 80 and 4x + 3y = 110
(d) 3x + 2y = 80 and 3x + 4y = 110
s) whether the estimation of Ramesh and Amar is applicable for Lokesh?​

Answer 1

SOLUTION

Here it is given that cost of one notebook be x and that of pen be y .

Then cost of 3 notebooks and 2 pens

Again cost of 4 notebooks and 3 pens

So by the given condition

Which is set of equations to describe the given problem

Hence the set describe the given problem is

(b) 3x + 2 y = 80 and 4x + 3 y = 110

Now we solve from x and y

Multiplying Equation (1) by 3 and equation (2) by 2 we get

On substraction we get x = 20

From Equation (1) we get y = 10

Hence cost of one notebook is 20 and that of pen be 10

Ramesh said that price of each notebook could be Rs. 25

So Ramesh's estimation is wrong

Amar felt that Rs. 2.50 for one pen was too little. It should be at least Rs. 16

So Amar's estimation is wrong

( II ) Whether the estimation of Ramesh and Amar is applicable for Lokesh

(d) Ramesh’s estimation is wrong but Amar’s estimation is also wrong.

Solving Equation (1) & Equation (2)

we get x = 20 & y = 10

( III ) The exact cost of the notebook

(b) Rs 20

( IV ) The exact cost of the pen

(a) Rs 10

The cost of 15 notebooks

= Rs ( 15 × 20 )

= Rs 300

The cost of 12 pens

= Rs ( 12 × 10 )

= Rs 120

Hence total cost

= Rs ( 300 + 120 )

= Rs 420

The total cost if they will purchase the same type of 15 notebooks and 12 pens.

(c) Rs 420

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Answer 2

Answer:

(b)

Step-by-step explanation: