Answer:
<u>Emma is currently 24 years.</u>
Step-by-step explanation:
Let B and E be Ben's and Emma's current ages, respectively.
We are told that:
B = 2E [Ben's age is currently twice of his sister, Emma.]
and
B-8 = 2.5(E-8) [8 years ago, Ben's age was 2 and a half times that of Emma's age]
We can substitute the vale of B (=2E) from the first equation into the second:
B-8 = 2.5(E-8)
(2E)-8 = 2.5(E-8)
2E-8 = 2.5E- 20
-0.5E = -12
E = 24
Emma is now 24 years old.
Ben would be 2E, or 48 years old.
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Check:
Eight years ago, they would be:
Ben = 40, and E = 16
40/16 = 2.5, which is the correct ratio of their ages 8 years ago.