Show:
4th Grade Math
5th Grade Math
5th Grade Math
6th Grade Math
Riddle Math
100
A digital clock shows 2:35. This is the first time after midnight when all three digits are different prime numbers. What is the last time before noon when all three digits on the clock are different prime numbers?
7:53 am
100
The only way that 10 can be written as the sum of 4 different counting numbers is 1 + 2 + 3 + 4. In how many different ways can 15 be written as the sum of 4 different counting numbers?
6 ways
100
Hannah gives clues about her six-digit secret number: Clue 1: It is the same number if you read it from right to left. Clue 2: The number is a multiple of 9. Clue 3: Cross off the first and last digits. The only prime factor of the remaining four-digit number is 11. What is Hannah’s six-digit number?
513315
100
An L-shape pictured is formed from three squares, each 1 cm on a side. Five of these L-shapes are placed next to each other to form a figure. What is the least possible perimeter of the figure they form, in cm?
16
100
The ages of a father and son add up to 66. The father's age is the son's age reversed. How old could they be? Give 2 out of the 3 possibilities!
The father-son duo could be 51 and 15 years old, 42 and 24 years old or 60 and 06 years old.
200
Solve: INK + INK + INK + INK + INK + INK = PEN (INK and PEN are 3-digit numbers, and different letters stand for different digits).
INK = 105, PEN = 630
200
DOUBLE THE POINTS!!! The number A2...2B has 2004 digits (all digits standing between A and B are 2). This number is divisible by 72. Find the digits A and B.
A = 6, B = 4
200
DOUBLE THE POINTS!!! A cubic number is of the form m^3 for some natural number m. For example, 8 is a cubic number since 8 = 2^3 How many cubic numbers exist between 2 and 999?
8
200
1/2 POINTS Each of the 39 students in the seventh grade at Jayhawk Middle School has one dog or one cat or both a dog and a cat. Twenty students have a dog and 26 students have a cat. How many students have both a dog and a cat?
7
200
Leo has $80 in his piggy bank and 20 bills. If he has four more $1 bills than $5 bills and 2 more $5 bills than $10 bills, how many bills of each denomination does he have?
He has four $10 bills, six $5 bills, and ten $1 bills
300
Seventy students took a Mathematics exam. 10% of them scored at least 90 points, 20% scored at least 80 but less than 90 points. How many students have scored less than 80 points?
49
300
A prime number is a natural number greater than 1 whose positive divisors are just 1 and itself. Twin primes are two primes whose difference is 2. For example, 3 and 5. Find twin primes whose sum is 60.
29 and 31
300
HALF THE POINTS!!! Two different circles overlap. The area of the overlapping region is 1/2 of the area of the smaller circle and is 1/6 of the sum of the area of the larger circle plus the area of the smaller circle. What is the ratio of the area of the smaller circle to the larger circle?
1:2
300
The sum of three consecutive whole numbers is 2010. What is the smallest whole number among the three numbers?
669
300
Draw a square on a piece of paper. Separate it into different regions by drawing 4 straight lines from one edge to another. What is the largest number of regions you can make?
11 regions
400
+100 POINTS!!!!! Slacks and shirts are on sale. The $25 slacks can be purchased at a 20% discount and the $18 shirts can be purchased at a 25% discount. What is the total cost, in dollars, of three pairs of slacks and 4 shirts at the sale price including 5% sales tax on the sale price?
119.70
400
-100 POINTS :( SORRY! If 8a − 6b = 24, what is the value of a/3 - b/4?
1
400
Erik has a bag of 58 balls, some are red and the rest are white. He removes some of the balls from the bag and notices that he removed 6 times more white balls than red. He observes that of the balls remaining in the bag, there are 5 times more red balls than white. How many balls did he remove from the bag and how many were red?
Removed 28 balls - 4 were red
400
+200 POINTS!!! A monkey is happy if it eats 3 types of fruit. There are 20 pears, 30 bananas, 40 peaches and 50 oranges. How do you distribute the fruit to make the most number of monkeys happy? What is this number?
Feed 5 monkeys with pear-banana-orange; feed 15 monkeys with pear-peach-orange; feed 25 monkeys with banana-peach-orange.
400
+250 POINTS!!! Jane had 4 three-cent stamps and 3 four-cent stamps. How many different amounts of postage can be made from these stamps?
18 different amounts
500
Sahn wants to donate books in his two bookshelves. The first bookshelf has 4 shelves with 16 novels on each shelf. The second bookshelf has 4 shelves with 14 science books on each shelf. Every book has the same size so Sahn evenly distributed those books into five boxes for packing. How many books will there be in each box?
24
500
Bob has a total of $41.00, consisting of an equal number of pennies, nickels, dimes, and quarters. How many coins does he have in all? (a) 50 (b) 100 (c) 150 (d) 200 (e) None of these
(e) None of these
500
If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 3 (for example, 20 is crossed out as 0 is divisible by 3 and 91 is crossed out as 9 is divisible by 3), how many numbers are crossed out?
54
500
A photographer is arranging five children in a row for a picture. Each child is wearing a different color hat. If the child in the red hat does not want to be placed on either end of the row and wants to be placed immediately to the right of the child in the blue hat, in how many ways can the five children be arranged?
18 ways
500
If DESIGNER is worth 47231578, RING is worth 8351, and SEND is worth 2754. What is NERD worth?
NERD is work 5784!