Question

The sum of the cost of one notebook and one pen together is 34 rupees and the difference between the cost of one notebook and the cost of one pen is 2 rupees. Then the cost of five notebooks and two pens together is

• A. 34 rupees
• B. 116 rupees
• C. 122 rupees
• D. 144 rupees

Answer 1

The correct option is C

122 rupees

Let the cost of one notebook be $x$ rupees and the cost of one pen be $y$ rupees.

Given, the cost of one notebook and one pen together is 34 rupees.

So, $x+y=34$ ---------- (i)

Also, given that, the difference between the cost of one notebook and the cost of one pen is 2 rupees.

So, $x-y=2$ ---------- (ii)

We know that $(x+y)+(x-y)=2x$ for all numbers $x$ and $y$.

$⟹34+2=2x$

$⟹x=18$

Now, $x-y=2$ and $x=18$ implies that $y=16$

Therefore , the cost of five notebooks and two pens together is $5x+2y=5\times 18+2\times 16=122\text{rupees}$