Answer:
1/20=10 years old
In a school 50% of the students are younger than 10, 1/20 are 10 years old and 1/10 are older than 10 but younger than 12, the remaining 70 students are 12 years or older. How many students are 10 years old?
50%= younger than 10
1/20=10 years old
1/10=older than 10 younger than 12
70=12 years or older
50%- 10/20
1/20-1/20
1/10-2/20
10/20+1/20+2/20=13/20
70 students =7/20
1/20 = 10 years old.
7/20 divided by 7 = 1/20
70 divided by 7=10
10 students are 10 years old