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(A) Future value = = = 4764.06 dollars.
(B) Interest in three years = 4764.06-4000 = 764.06 dollars.
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If (C) is self-standing separate problem, then why do you post two separate problems in this post ?
The rule of this forum is
ONE and ONLY ONE problem per post.
Those who violate this rule, work against their own interests.