Mary has two sisters. Her younger sister is 5 years younger Her older sister is twice her age. Their ages add up to 47. How dd is Mary and each
of her sisters?

Older sister is 26, Mary is 13, and younger sister is 8.
Explanation:
26 + 13 + 8 = 47
If the older sister is 26, then Mary is half that, meaning: 26/2 = 13
Mary is 13, and her younger sister is 5 years younger so: 13-5 = 8
Her younger sister is 8.
To double check, add up the ages and see if you get 47.
26 (older sister) + 13 (Mary) + 8 (younger sister) = 47

Hello!
volume of sphere =4/3.pi.r^3