Ben had 1/5 as many books as Jann. After Jann gave Ben 4 books, Ben had 1/3 as many books as Jann. How many books did Jann have in the end?
Ben had 1/5 as many books as Jann. After Jann gave Ben 4 books, Ben had 1/3 as many books as Jann. How many books did Jann have in the end?
B = (1/5) • J —>> J = 5B (eq 1)
(B+4) = (1/3) • (J–4) —>> 3 • (B+4) = J–4
3B + 12 = J – 4
J = 3B + 16 (eq 2)
set (equation 1) equal to (equation 2) in terms of B
5B = 3B + 16
2B = 16
B = 8
referring back to (equation 1) J = 5B
J = 5 • 8
J = 40 this is how many books Jann started with
Jann gives away 4 books 40 – 4 = 36 this is how many books Jann ended up with
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