a. The number of teenagers that like hard rock is of: 272.
b. The number of teenagers surveyed is of: 200.
c. A percentage greater than 100% is when the percentage of an amount is calculated relative to an smaller amount.
The measures are obtained applying the given proportions and percentages in the context of the problem.
For item a, the amount is of 32% of 850, hence:
0.32 x 850 = 272 teenagers like hard rock.
For item b, we have that 75% = 0.75 of the amount x is of 150, hence the total amount of teenagers surveyed is obtained as follows:
0.75x = 150
x = 150/0.75
x = 200 teenagers were surveyed.
A percentage is calculated as the division of an amount a by an amount b. Hence, if the amount a is greater than the amount b, the percentage will be greater than 100%.
More can be learned about proportions at https://brainly.com/question/24372153
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