Question

y varies directly as x and inversely as z. If y = 5 when x = 3 and z = 4, find y when x = 6 and z = 8.

Answer 1

y= 201/40

Explanation:

y=k (x÷z)

5 = (3÷4)k

cross multiply

20=3k

k= 6.7 or 67÷10

y = 6.7 (x÷z) the law

y = (6÷8) × 6.7

y = 0.75 ×6.7

y= 5.025 or 201÷40