Math Problem Monday - Feb 5th, 2018 | Mathnasium Livermore, CA

Feb 5, 2018 | Livermore

Lower Elementary
Question: In two years Sharon will be twice as old as her sister Jennifer.  The sum of their ages today is 14.  How old is Jennifer?
Answer: 4 years old
Note: Use guess and check method.

Upper Elementary
Question: Use the list of numbers below.
9  14  5  13  10  3  7  8  6  2
Cross out two numbers with a difference of 6 and a product of 91.  Then cross out two numbers with a a sum of 13 and a  difference of 3.  Next, cross out two numbers that have a quotient of 5 and a difference of 8.  Finally cross out tow numbers with a difference of 6 and a quotient of 3.  What is the sum of the numbers that are left?
Answer: 20 (numbers that are left are 14 and 6)
Note:
1.  There are three pairs of numbers with a difference of 6. 9 and 3, 13 and 7, and 8 and 2.  However only 13 and 7 have a product of 91.  Cross out 13 and 7.
2.  There are two pairs of numbers with a sum of 13.  8 and 5 and 10 and 3.  However, only 8 and 5 have a difference of 3.  Cross out 8 and 5.
3.  There is only one pair of numbers left that has a quotient of 5 and difference of 8, 10 and 2.  Cross out 10 and 2.
4.  There is finally only one pair of numbers that have a difference of 6 and a quotient of 3, 9 and 3.  Cross out 9 and 3.
The numbers that are left are 14 and 6.

Middle School
Question: The area of a square is 40 square inches.  A new square is made by quadrupling each of the side lengths of the original square.  What is the area of the new square?
Answer: 640 square inches.
Note:  The area of a square is equal to side times side.  A = s x s = s2.  If each of the sides is quadrupled then the new side length is 4 times s or 4s.  That means the area of the new square is 4s x 4s.  That means the new square has an area of 16(s x s) or 16s2.  If the area of the original square is 40 then the area of the new square is 16 x 40 = 640.

Algebra and Up
Question: A sculpture garden has two different sized sculptures in the shape of rectangular prisms.  The larger rectangular prism weighs 4 tons.  Each dimension of the smaller prism is one quarter of those of the larger prism.  Find the weight of the smaller prism (in pounds).
Answer: 125 pounds
Note:  The weight of the larger prism in pounds is 8000.  (1 ton = 2000 pounds.)  To find the weight of the smaller prism find the fraction the smaller prism is of the larger prism.  The volume of the larger prism is V =  l x w x h.  Since each dimension of the smaller prism is 1/4 of each dimension of the larger prism, the volume of the smaller prism is 1/4l x 1/4w x 1/4h = 1/64V.  That means the smaller prism is 1/64 of the larger prism.  The weight of the prism will be 1/64 of the larger prism.  1/64 x 8000 pounds = 125 pounds.

Math tutors near

Could not find Center, try again