Question

The cost of a pen was 2 whole 2 by 5 times of the cost of a pencil if the pencil cost rupees 5 what was the cost of a pen

Answer 1

Answer:

let's assume that we buy x pencils, y pens, and z notebooks.

then the number of items we buy would be x+y+z, and the total cost incurred would be 0.05x+0.5y+5z. so we have the equations:

Step-by-step explanation:

x+y+z=100

0.05x+0.5y+5z=100

eliminating x from this system gives the equation 9y+99z=1900. since the LHS of this equation is a multiple of 9 but the RHS is not, we can realize that the equation has no integer solution. and since our variables represent number of items, they must be integers.

therefore we can conclude that it is impossible to buy exactly 100 items spending exactly ₹100.