1 7/9 - 4/9
Convert 1 7/9 to an improper fraction:
16/9 - 4/9
Subtract the numerators together:
12/9
Convert to a whole number:
1 1/3
There will be a 25 grams left after 3240 years.
The half-life of Radium-226 is 1620 years. If we divide 3240 by 1620 the answer is 2. So that means the amount of Radium-226 will divide in half twice.
100 / 2 = 50 / 2 = 25
Glass and Titanium. Glass is because (10,40) (y over x) is 4 and Titanium is because (10,60) is 6 cork and lead are not since when dividing y over x it doesn't equal 2.