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7. The following expressions make sense but are invalid according to C++'s rules of syntax. Rewrite them so that they are valid logical expressions. (All the variables are of type int.) |
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a. x < y <= z |
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b. x, y, and z are greater than 0 |
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c. x is equal to neither y nor z |
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d. x is equal to y and z |
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8. Given these values for Boolean variables x, y, and z: |
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x = TRUE, y = TRUE, z = FALSE |
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indicate whether each expression is TRUE (T) or FALSE (F). |
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______ a. ! (y | | z) | | x |
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______ b. z && x && y |
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______ c. ! y | | (z | | !x) |
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______ d. z | | (x && (y | | z)) |
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______ e. x | | x && z |
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9. For each of the following problems, decide which is more appropriate, an If-Then-Else or an If-Then. Explain your answers. |
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a. Students who are candidates for admission to a college submit their SAT scores. If a student's score is equal to or above a certain value, print a letter of acceptance for the student. Otherwise, print a rejection notice. |
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b. For employees who work more than 40 hours a week, calculate overtime pay and add it to their regular pay. |
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c. In solving a quadratic equation, whenever the value of the discriminant (the quantity under the square root sign) is negative, print out a message noting that the roots are complex (imaginary) numbers. |
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d. In a computer-controlled sawmill, if a cross section of a log is greater than certain dimensions, adjust the saw to cut 4-inch by 8-inch beams; otherwise, adjust the saw to cut 2-inch by 4-inch studs. |
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10. What causes the error message UNEXPECTED ELSE when this code fragment is compiled? |
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if (mileage < 24.0)
{
cout << Gas ;
cout << guzzler.;
};
else
cout << Fuel efficient.; |
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11. The following code fragment is supposed to print Type AB when Boolean variables typeA and typeB are both TRUE, and print Type O when both variables are FALSE. Instead, it prints Type O whenever just one of the variables is FALSE. Insert a { } pair to make the code segment work the way it should. |
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if (typeA || typeB)
if (typeA && typeB)
cout << Type AB;
else
cout << Type O; |
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