Fresh 3 Flashcards
(9 cards)
Each of the digits 7, 5, 8, 9 and 4 is used only one to form a three digit integer and a two digit integer. If the sum of the integers is 555, how many such pairs of integers can be formed?
4
If x is the product of the integers from 1 to 150, inclusive, and 5y is a factor of x, what is the greatest possible value of y ?
37
The question basically asks how many 5s are in 150!.
To find how many x’s are in y! use the following formula:
y/x + y/x2 … + y/xn (as far as xn < y) approximated to the biggest integer.
Thus,
nr of 5’s in 150! = 150/5 + 150 /25 + 150/125 = 30 + 6 + 1 = 37
The vertices of a rectangle in the standard (x,y) coordinate place are (0,0), (0,4), (7,0) and (7,4). If a line through (2,2) partitions the interior of this rectangle into 2 regions that have equal areas, what is the slope of this line?
1
What is the value of x^2 - y^2?
(1) x + y = 2x
(2) x - y = 0
D.
In a certain region, the number of children who have been vaccinated against rubella is twice the number who have been vaccinated against mumps. The number who have been vaccinated against both is twice the number who have been vaccinated only against mumps. If 5,000 have been vaccinated against both, how many have been vaccinated only against rubella?
10.000
The measurements obtained for the interior dimensions of a rectangular box are 200 cm by 200 cm by 300cm. If each of the three measurements has an error of at most 1 centimeter, which of the following is the closes maximum possible difference, in cubic centimeters, between the actual capacity of the box and the capacity computed using these measurements?
The options are well spread so we can approximate.
Changing the length by 1 cm results in change of the volume by 1*200*300 = 60,000 cubic centimeters;
Changing the width by 1 cm results in change of the volume by 200*1*300 = 60,000 cubic centimeters;
Changing the height by 1 cm results in change of the volume by 200*200*1 = 40,000 cubic centimeters.
So, approximate maximum possible difference is 60,000 + 60,000 + 40,000 = 160,000 cubic centimeters.
0.4
In the decimal 3.1de, d and e each represent a digit. If x represents the decimal 3.1de rounded to the nearest tenth, what is the value of x?
(1) d=4
(2) e=8
A.
When we have to round to the tenth we look only at the hundreth.
Is quadrilateral ABCD a square if two of his angles equal 90 degrees?
No.
If two angles equal 90 degrees all we know is that the quadrilateral is a paralelogram. It might not be a square. We need additionaly to know the lengths of the sides in order to determine if it is a square.
