## <!-- -->To run this page correctly, you need a more modern browser that understands JavaScript.<P><!--Beginning of JavaScript function checkanswer() { //var f=document.question; r=0;r1=0; r2=0; if (f.ann.selectedIndex==3){f.A.src=imaged[2].src; r++} else {f.A.src=imaged[3].src;} if (f.betty.selectedIndex==4){f.B.src=imaged[2].src; r++} else {f.B.src=imaged[3].src;} if (f.carol.selectedIndex==3){f.C.src=imaged[2].src; r++} else {f.C.src=imaged[3].src;} if (f.cs1.value==90.) {f.E.src=imaged[2].src; } else {f.E.src=imaged[3].src; r1=1} if (f.cs2.value==285) {f.F.src=imaged[2].src; } else {f.F.src=imaged[3].src;; r2=1} if (f.total.selectedIndex==8){f.D.src=imaged[2].src; r++} else {f.D.src=imaged[3].src;} a1="Very good." if (r2==1) a1="Ann and Carol each get \$90 of surplus and Betty gets \$105. What is the total?"; if (r1==1) a1="Ann will buy two pair of shoes. She gets a total value of \$120 (\$100 for the first plus \$20 for the second) but pays \$30. What is her surplus?"; if (r<4) a1="Keep trying. You need to figure out the number of shoes before you can find the consumer surplus."; f.comment.value=a1; } //-End of JavaScript- -->

3. Ann, Betty, and Carol are three buyers of shoes. Their demand curves are shown below in terms of their willingness to pay.

 Number of Pairs Marginal Benefit measured as willingness to pay of: Ann Betty Carol First \$100 \$80 \$90 Second 20 40 30 Third 10 30 10 Fourth 5 10 2 Fifth 2 5 1

a) If the price of shoes is \$15, how many pairs will Ann buy?

a) If the price of shoes is \$15, how many pairs will Betty buy?

c) If the price of shoes is \$15, how many pairs will Carol buy?

d) If the price of shoes is \$15, how many pairs of shoes will be bought in total?

e) What will Ann's consumer surplus be at this price? \$

f) What will the total consumers' surplus be? \$