Question 1017781
n = 3d
0.05n+0.10d = 25 substitute for n
0.05(3d)+0.10d = 25
0.15d+0.10d = 25
0.25d = 25
d = 100
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n/3 = d
0.05n+0.10d = 25 substitute for d:
0.05n+0.10(n/3) = 25
0.15n+0.10n = 75
0.25n = 75
n = 300
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Check:
d = 100*0.10 = 10
n = 300*0.05 = 15
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Total. . . . . 25 We  have the correct answer