Math problems for September 30 2011

Problem #1
A slow clock loses 3 minutes every hour. Suppose the slow clock and a correct clock both show the correct time at 9 am. What time will the slow clock show when the correct clock shows 10 o'clock the evening of the same day?


Problem #2


The figure below is a 'magic square' with missing entries. When complete, the sum of the four entries in each column, each row, and each diagonal is the same. Find the value of A and the value of B.





Problem #3


The digit 3 is written at the right of a certain two-digit number thus forming a three-digit number. The new number is 372 more than the original two-digit number. What was the original two-digit number?


Problem #4


ABCD is a square with area 16 sq. meters. E and F are midpoints of sides AB and BC, respectively. What is the area of trapezoid AEFC, the shaded region?





Problem #5


Peter agreed to work after school for 8 weeks at a fixed weekly rate. But instead of being given only money, he was to be given $85 and a bicycle. However, Peter worked only 5 weeks at the fixed weekly rate and was given $25 and the bicycle. How much was the bicycle worth?

Math problems for Sept. 23 2011

Problem #1


The serial number of my camera is four-digit number less than 5,000 and contains the digits 2, 3, 5, and 8 but not necessarily in that order. The '3' is next to the '8', the '2' is not next to the '3', and the '5' is not next to the '2'. What is the serial number?


Problem #2


One day, Carol bought apples at 3 for 25 cents and sold all of them at 2 for 25 cents.If she made a profit of $1 that day, how many apples did she sell?


Problem #3






As shown, ABCD and AFED are squares with a common side AD of length 10 cm. Arc BD and arc DF are quarter-circles. How many square cm, are in the area of the shaded region?


Problem #4


When the same whole number is added to both the numerator and denumerator of 2/5, the value of the new fraction is 2/3. What number was added to both the numerator and denumerator?


Problem #5


The sum of the ages of three children is 32. The age of the oldest is twice the age of the youngest. The ages of the two older children differ by three years. What is the age of the youngest child?

Math problems for September 16

Problem #1


In the subtraction problem below, each letter represents a digit, and different letters represent different digits.
What digit C represents?





Problem #2



Each of the small boxes in the figure below is a square. The perimeter of square ABCD is 36 cm. What is the perimeter of the figure shown with darkened outline?







Problem #3



means 2 x 2 x 2 or 8



means 3 x 3 x 3 or 27



means N x N x N


Suppose

is equal to 4913. What is the value of N?


Problem #4





Carl shot 3 arrows; 2 landed in the A ring and 1 landed in circle B for a total score of 17. David also shot 3 arrows; 1 landed in A and 2 in B for a total score of 22. How many points are assigned to B?


Problem #5


In the following sequence of numbers, each number has one more 1 than the preceding number: 1, 11, 111, 1111, ... . What is the tens digit of the sum of the first 30 numbers of the sequence?


Homework


Problem #1


My age this year is a multiple of 7. Next year it will be a multiple of 5. I am more than 20 years of age but less than 80. How old will I be 6 years from now?

9999999

Place parentheses and mathematical operations (+, -, /,*) on the left of the following equation to make it correct

9999999 = 100

Math problems for May 10 2011

Problem #1



How many times does X occurs in the diagram here.




Problem #2


The product of three counting numbers is 24. How many different sets of 3 numbers have this property if the order of the 3 numbers in a set does not matter?



Problem #3


Carol spent exactly $1 for some 5 cents stamps and some 13 cents stamps. How many 5 cents stamps did she buy?






Problem #4








In the addition problem here, there are three two-digit numbers in which different letters represent different digits. What digits do A, B, and C represent?





Problem #5


Let N be a number that divides 171 with a remainder of 6. List all the two-digit numbers that N can be.


Problem #6


The result of multiplying a counting number by itself is a square number. For example, 1, 4, and 9 are each square numbers because 1X1=1, 2X2=4, and 3X3=9. What year in the 20th century (the years 1901 through 2000) was a square number?



Problem #7


A group of 12 girls scouts had enough food to last for 8 days when they arrived in camp. However, 4 more scouts joined them without the amount of food being increased. How long will the food last if each scout is given the same daily ration as originally planned?

Brain Teaser of the week

A cylinder 60 cm high has a circumference of 16 cm. A string makes exactly 5 complete turns round the cylinder while its two ends touch the cylinder's top and bottom. How long is the string in cm?

To check the answer come back on May 12

Math problems for May 3 2011

Problem #1
The average of three numbers is 6. Let the first number be increased by 1, the second by 2, and the third by 3. What is the average of the set of increased numbers?


Problem #2

The month of January has 31 days. Suppose January 1 occurs on Monday. What day of the week is February 22 of the next month?


Problem #3



The set of stairs (see below) is constructed by placing layers of cubes on top of each other. What is the total number of cubes contained in the staircase?



Problem #4


When a counting number is multiplied by itself, the result is a square number. Some examples of square numbers are 1, 4, 9. How many square numbers between 1 and 100?


Problem #5


The product of two whole numbers is 10,000. If neither number contains a zero digit, what are the two numbers?


Problem #6


Of three numbers , two are 1/2 and 1/3. What should the third number be so that the sum of all three is 1?


Problem #7


The four-digit number A55B is divisible by 36. What is the sum of A and B?
Hint: A number is divisible by 36 if it is divisible by 9 and 4 (so it is even)