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Before we start, did you try solving the workbook yourself?

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If not, please click the link in the resources folder and follow the instructions for this workbook.

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This video will present the solution to workbook 2.1.

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Please make sure that you launched the exact folder that contains your Java file.

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So here we have a points, a variable that starts zero, and we need to keep updating the number of

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points in accordance with these print statements.

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First, Harry loses 50 points for Gryffindor, so here we have to say points minus equal 50.

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By saying that it updates the variable on the left by subtracting the value on the right.

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So once we reach this line, now points is going to equal -50.

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And next, Harry was being cheeky in class, this time losing Gryffindor.

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Three points.

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So here we have to say points.

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Minus equal three.

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So at this line, points should equal -53.

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But this time her mini wins 30 points for Gryffindor.

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So here by saying points plus equals 30, it updates the variable on the left by adding the value on

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the right.

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And now here run earned 100 points so we can add another 100 points to the points variable.

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And finally Harry redeemed himself and earned 60 points.

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So here I can add 60 to my points variable.

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And Task two is fairly easy.

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You simply need to print your final result and run your code.

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So here I will say system, dot, dot, print line, the final number of points.

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Now I will go run my code using terminal commands.

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Java C points.

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Dot Java.

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Java points.

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And we get the correct result.

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137.

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Let's visualize the runtime.

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The variable starts at zero, and in the first two cases it updates the points variable by subtracting

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the value on the right.

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In the last three cases, it updates the points variable by adding the value on the right, and the

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final result is 137.