What is the value of sin a? a. 9/12 b. 12/9 c. 9/15 d. 12/15

Pelle's sister is three years older than pelle the father is 5 times as old as pelle the mother was 28 when the sister was born altogether they are 98 years old how old is pelle?

1. during first 10 seconds 2. between 10 seconds and 35 seconds 3. during 35 seconds to 40 seconds

Ineed in figuring out this problem.