Question

for a class copies of 9 maths books and 16 science books cost Rs.220 . Eachbook costs a whole number of rupees.Find the cost of each math book

Answer 1

Answer:

The cost of each Maths book is Rs. 12

Step-by-step explanation:

Let the cost of each maths book is x Rs. and each science book is y Rs.

Then according to the question

$9x+16y=220$

Since x and y are positive integers

Therefore we have to use hit and trial method to find out x and y

From the above

$x=\frac{220-16y}{9}$

If we take $y=7$, then

$x=\frac{220-16\times 7}{9}$

$\implies x=\frac{220-112}{9}$

$\implies x=12$

Which comes out to be a positive value

Therefore, the cost of each Maths book is Rs. 12

Hope this answer is helpful.

Answer 2

Answer: The cost of each math book is Rs. 12

Step-by-step explanation:

Let the cost of Math books =Rs. x

Let the cost of science books = Rs. y

According to question we have

$9x+16y= 220\\\\\Rightarrow  x= \dfrac{220-16y}{9}$

As the cost of each book is whole number

So by hit and trail method we get y = 7

Therefore  

$x= \dfrac{220-16y}{9}\\\\\Rightarrow \dfrac{220-16\times 7}{9}= \dfrac{108}{9} =12$

Hence, the cost of each math book is Rs. 12