2009 AMC 10A Problem 18

Question

At Jefferson Summer Camp,

60\%

of the children play soccer,

30\%

of the children swim, and

40\%

of the soccer players swim. To the nearest whole percent, what percent of the non-swimmers play soccer?

30\%

40\%

49\%

51\%

70\%

Assume

100

children and count soccer players who swim

Find how many of the

70

non-swimmers play soccer

Take

100

children:

60

play soccer, and

40\%

of them, or

24,

also swim. So

60 - 24 = 36

soccer players do not swim.

There are

30

swimmers and

70

non-swimmers, so the fraction of non-swimmers who play soccer is

\dfrac{36}{70} \approx 0.514 \approx 51\%.

Thus, the correct answer is D.

Problem 18 in other years