Solve the problem and pick the best answer from the choices.

Step-by-step explanation:

the third answer is correct.

with a $20 card we can pay for calling costs up to $20 (including $20).

the calling costs are $0.03 per minute in the US, and $0.06 per minute to Brazil.

so, we need to multiply every calling minute in the US by 0.03, and every calling minute to Brazil by 0.06. both results need to be added up.

and the total sum cannot be more than $20.

so

0.03x + 0.06y <= 20

is correct.