(a) 40% of 15
40% of 15 = (40/100)(15) = 600/100 = 6

or...
40% of 15 = (0.4)(15) = 6

or....
10% of 15 = 1.5
So, 20% of 15 = 3
So, 40% of 15 = 6
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(b) 150% of 48
150% of 48 = (150/100)(48) = (3/2)(48) = 72

or...
150% of 48 = (1.5)(48) = 72

or...
100% of 48 = 48
So, 50% of 48 = 24
So, 150 of 48 = 48 + 24 = 72
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(c) 0.6% of 800
0.6% of 800 = (0.6/100)(800) = (6/1000)(800) = 4800/1000 = 4.8

or...
0.6% of 800 = (0.006)(800) = 4.8

or...
1% of 800 = 8
So, 0.1% of 800 = 0.8
So, 0.6% of 800 = 4.8
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(d) 15 is 30% of which number?
Rewrite as: 30% of x = 15
Rewrite as: (30/100)x = 15
Simplify: 0.3x = 15
Solve: x = 15/0.3 = 150/3 = 50
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(e) 11 is what percent of 55?
Rewrite as: x% of 55 = 11
Rewrite as: (x/100)(55) = 11
Simplify: 55x/100 = 11
Multiply both sides by 100 to get: 55x = 1100
Solve: x = 1100/55 = 220/11 = 20%
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