Area, Weight

[Guest]

A 15 inch square piece of metal weighs 1.5 lbs. A 15 in. circle is removed from the square. Determine area and weight of the circle.

My attempt;

Area of circle: pi * r^2.
3.1416 * 7.5 * 7.5 = 176.71 sq. in.

15 * 15 = 225 sq. in. (area of square)

225 / 144 = 1.56 sq. ft.

Unsure how to calculate the weight.

[Guest]

Area of circle: pi * r^2.
3.1416 * 7.5 * 7.5 = 176.71 sq. in. .....This is area of the circle

15 * 15 = 225 sq. in. (area of square) ......This is area of the square ....all of it and it weighs 1.5 lbs

225 / 144 = 1.56 sq. ft. ........don't know what you are doing here...??????

Applying some logic.......

225 sq.ins weigh 1.5 lbs ..... find how much 176.71 sq ins....???????

units conversion..... 1 lb equals 16 ozs ....so 1.5 lbs equals 24 ozs

1 sq ins. weighs 1.5 / 225 lbs OR 24 / 225 ozs.

So 176.71 sq ins. will weigh 176.71 x (24 / 225) ozs.

[Guest]

" 225 / 144 = 1.56 sq. ft. ........don't know what you are doing here...?????? " Converted to sq. ft. ; Unnecessary calculation.

1.5 / 225 = 0.0066

0.0066 * 176.71 = 1.166 = 1.17 lbs.

Thanks.

[Guest]

So 176.71 sq ins. will weigh 176.71 x (24 / 225) ozs...... = 18.849 ozs.

[Guest]

" So 176.71 sq ins. will weigh 176.71 x (24 / 225) ozs...... = 18.849 ozs. "

18.849 / 16 = 1.178 lbs.

Thanks again.