When you were 4 she was 2. You were two years older than she was. So if you are now 100 she is 98
If you mean "now you are 100 years old", then, my sister is now 98 years old, since she was 2 when I was 4.
If when you were 2 years old your sister was half of your age, you would have been 2 and she would have been 1. So she is one year younger than you. Thus now you are 100 she will be one year younger and aged 99.
A century is 100 years, so half a century = 100/2 which makes 50 years.50 years.
a century is 100 years so half of that is 50 years
One half a century equals 50 years as a century equals 100 years.
99
If you mean "now you are 100 years old", then, my sister is now 98 years old, since she was 2 when I was 4.
98
If when you were 2 years old your sister was half of your age, you would have been 2 and she would have been 1. So she is one year younger than you. Thus now you are 100 she will be one year younger and aged 99.
100 years
A century is 100 years, so half a century = 100/2 which makes 50 years.50 years.
a century is 100 years so half of that is 50 years
After 100 years, half of the original sample (20 grams) will remain. After another 100 years (total 200 years), only half of that amount (10 grams) will remain.
If you have four seasons in a year, then there will be 400 in 100 years.
Since a century is 100 years, half a century would be 50. So, the answer is 50 years.
One half a century equals 50 years as a century equals 100 years.
If the substance has a half-life of 10 years, there would be 10 half-lives in a 100-year span. Each half-life reduces the amount by half, so after 100 years, 1/2^10 = 1/1024 grams of the sample would remain.