Math Problem of the DayApril 2013

If Mark’s first three test scores are 95, 88, and 100, what score must he make on the next test to have a test average of 90?

4/1 Better than Average

Luther began reading a 200 page book at 1:15 PM, and he had read 40 pages by 2:00 PM. If he continues to read at the same rate, how many minutes will it take him to read the rest of the book?

4/2 Reading and ‘Rithmetic

The vertex angle of an isosceles triangle measures 18o. What would the bases angles of the triangle be if the length of each side the triangle were doubled?

4/3 An Isosceles Issue

If Lexi slices a pie into eight congruent pieces, and then takes three and a half pieces, what percent of the pie is left?

4/4 A La Mode

If the perimeter of the large outer rectangle is 32 units, what percent of the large rectangle is shaded gray?

4/5 Find the Percent

What number multiplied by 7 is exactly equal to one more than itself?

4/8 Lucky Sevens

John ran three laps around the school track. He completed the first lap in 5 minutes. The second lap took 20% longer to complete than the first. The third lap took 30% longer to complete than the second. What was John’s total running time for the three laps?

4/9 Running in Circles

Square ABCD is partitioned into nine congruent squares, with the center square partitioned again into nine congruent squares. What fractional part of square ABCD, shown here, is shaded?

4/10 Fractions of Fractions

In the set {2, 5, 11, 17, 20} what is the difference between the mean and the median?

4/11 What Do You ‘Mean’?

Mrs. Smith sold her old car to a collector for a price of $16,000, which was 150% more than its original price. What was its original price?

4/12 Let’s Make a Deal

12

For the first half of a bicycle trip, Vince rode downhill at 24 mph for 2 hours. During the second half of the trip, he rode uphill at half his downhill speed for twice as long before returning to his starting point. What was Vince’s average speed, in mph, for his entire trip?

4/23 Ups and Downs

If a fair coin is tossed three times, what is the probability that heads shows at least once and tails shows at most twice? Express your answer as a fraction.

4/24 Heads or Tails?

15

16

The perimeter of a particular rectangle is eight times its width. If the area of the rectangle is 243 in2, what is the width of the rectangle?

4/29 Perimeter Problem

What is the value of the expression below?

4/30 Three times the challenge

3⋅3+ 3(3+ 3)−33

Problems adapted from Mathcounts 2012 School Countdown.