Place parentheses and mathematical operations (+, -, /,*) on the left of the following equation to make it correct
9999999 = 100
Saturday, May 21, 2011
Monday, May 9, 2011
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?
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?
Wednesday, May 4, 2011
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
To check the answer come back on May 12
Monday, May 2, 2011
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)