United States currency is printed using intaglio presses that generate a printing pressure of 8.60 104 lb/in2. A $20 bill is 6.1 in. by 2.6 in. Calculate the magnitude of the force that the printing press applies to one side of the bill.

The force exerted on the bill is .

Explanation:

Given:

The pressure generated by the press,

A $20 bill has the length, and breadth, .

The force on any object is given by

where is the pressure and is the area of the object.

The area of the bill is

The force exerted on the bill is

mass and volume are the answers you are looking for

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form