gb
     Test     
-Dr.
com
hz

FOURTH GRADE / MATHEMATICS /SUBTRACTION of FRACTIONS 1.2

MATHEMATICS IS EASY. PROVIDED THAT ONE WORKS ENOUGH .
ENOUGH IS SKILL DEPENDENT, HAVE TO FIND "ENOUGH" FOR YOUR SIZE.

   WITH INCLUSION of FRACTIONS
 ♦ 
COUNTING BACKWARDS TENDS TO BE  ADDING END-TO-END, THE NEGATIVE ONE POINTING BACKWARDS, SUBTRACTION.
 ♦ HOWEVER BIG/SMALL THEY ARE, WE SHOULD BE ABLE TO SUM & SUBTRACT.

THERE ARE TWO GOLDEN RULES:
1. DENOMINATORS SHOULD BE EQUAL, OR EXPANDED/REDUCED AND MADE EQUAL.
2. THE MOST EFFICIENT WAY GOES THROUGH THE LEAST COMMON DENOMINATOR (LCD).
y
1. Clevronia Democratic Republic has weighted votes. A college graduate has weight 2, citizens having masters degrees have weight 3 and PhD's weight is 4. Its distribution of population as well as weights is shown in the table below.
The elections in 2020 was boycotted by all PhD's because of ignorance of their rights. What will be the fraction of used weight adjusted votes if all other groups completely used their votes, all valid ?


In case of need for tips get the cursor on "y" or for help click at "ry1/2" .
RY1 RY2



a) 1/7
b) 4/35
c) 3/37
d) 5/71


Have a look at ry1 .
y
2. After an election in Clevronia of question 1 it was observed that 1/25 ths of the votes with weight 1 , 1/30 ths of weight 2, 1/35 ths of weight 3 and 1/40 ths of weight 4 were invalid.
What is the fraction of weight adjusted total valid votes.


In case of need for tips get the cursor on "y" or for help click at "ry1/2" .

RY1 RY2



a) 3787/3938
b) 81/2450
c) 2369/2450
d) 99/3333
Have a look at ry1 .
3. Which choice corresponds to the figure ?

!


a) 1 1/5 + 1 1/5 - 1 3/5 = 4/5
b) 1/5 + 1 1/5 - 1 3/5 = 3/5
c) 1 1/5 + 1/5 - 1 3/5 = 3/5
d) 1 1/5 + 1 1/5 - 1 3/5 = 3/5
First an addition and then a subtraction ... .
4. 1/2 - 1/3 + 1/4 - 1/5 + 1/6 - 1/7 + 1/8 = ?

a) 71/88
b) 333/846
c) 305/787
d) 307/840
Apply the method given in question 2 .
5. 9/4 - 3/4 + 3/2 - 3 = ?

a) 1
b) 0
c) 1/2
d) 2/3
The sum of first two is 3/2 .
6. 2360 / 2664 - 372 / 444 = ?

a) 22/333
b) 11/163
c) 77/117
d) 74/109
295 /333 - 31 / 37 and 333 = 9 x 37.
7. What should F be, if F + 1 3/4 + 3 3/8 = 8 1/3 is known ?

a) 3 5/24
b) 2 3/14
c) 1 1/5
d) 4 4/9
F+4+6/8+3/8 = 8+ 1/3 i.e. F+1/8 = 3+1/3 which means F=3+1/3-1/8=3+5/24 = 3 5/24 .
8. Gary spent fourteen twentyfirsths of his monthly salary in the first half of June. How much of his salary will he have for the rest of the month ?

a) one-fifths
b) two-thirds
c) one-thirds
d) two-sevenths
The whole is 21/21 ths .
9. (5 - 1/5) - (2 - 2/5) ?

a) 1 4/9
b) 3 1/5
c) 5 15/27
d) 61/28


First parenthesis : 24/5 .
Second par. : 8/5
10. The World has about 4 000 million hectares of forest area. Depending on the year some 6-14 million hectares of this area gets fire and burns.
What is the ratio of this difference of maximally and minimally burning areas to the whole forest area ?

!


a) 1/5000
b) 1/1000
c) 1/100
d) 1/500
8/4000 = 1/... .
11. An internet source reports tat "Based on the factors described above, a realistic estimate of global road deaths is between 750,000 and 880,000 for the year 1999."
Taking a population of 6 billion, what is the relative accuracy of the estimation given above ?

!


a) 13/75
b) 15/97
c) 17/121
d) 19/189
Relative accuracy has nothing to do with the global population. It is the difference of the numbers divided by the smaller number .
12. What will be the result of the expression in the figure below ?

!
a) 1
b) 2
c) 3/2
d) 4/3
1 - 1/2 = 1/2 ; 1/(1/2) = 2 (inverse of an half is two; there are two halfes in a unit) & - 1 /(-1) = 1.
13. Which of the following subtractions are true ?

I: 44/77 - 77/154 = 1/14
II: 66/77 - 44/77 = 11/77
III:1/2 - 1/3 = 1/2
IV: 323/333 - 83/111 = 74/333


a) I and III
b) II and III
c) only I
d) I and IV
I is 4/7 - 7/14 = 1/14.
II and III are wrong, check IV
14. What is the value of a/b if (a-b)/b = 3/2 ?

a) 5/2
b) 3/2
c) 4/3
d) 7/3
a/b - 1 = 3/2 gives a/b = 5/2 .
15. What is to be expected as the rounded after the decimal dot outcome ?

!


a) 9
b) 6
c) 4
d) 2
22/7 is practically π .
We have 2xπ - 1/11 & 1/11 = 0.09
6.28 - 0.09 will be 6.19 and rounded it will be ...
16. Which of the following operations gives the minimal result ?

I :2/8 - 1/7 = ?     II : 2/10 - 1/9 = ?      III : 2/12 - 1/11 = ?       IV : 2/14 - 1/13 = ?

a) III
b) II
c) IV
d) I
In which case are the operands nearest to each other ?
Think in the form I : (14-8)/56 = 6/56 ; II (18-10)/90 = 8/90 ...
17. Which box' content should replace the question mark ?

!


a) yellow
b) purple
c) orange
d) green
Do not hesitate, just do what you know. It will be enough.
18. One tenths of a pool can be emptied by one particular pipe , whereas a different pipe fills 1/6 ths of it, both in an hour. How long would it take to fill the pool with both pipes turned on ?

!


a) 5
b) 10
c) 15
d) 18
What would happen in an hour ? Answer is simple : 1/6 - 1/10 = 1/15 which means one fifteenths of the pool would be filled.
19. 17 11/65 - 3 12/95 = ?

a) 7
b) 14 53/1235
c) 11
d) 17
First subtract the wholes : 17 - 3 = 14 .
Common denominator is 17x13x5=1235 ; 1235/65=19 and 1235/95=13.
11x19=209 and 12x13=156 so we have as the fractional part ...
20. 2 27/35 - 118/90 = ?

a) 27/37
b) 51/39
c) 63/41
d) 92/63
Separate the whole part . C. d. is 630 , 630/35 = 18 and ... .
18x27=486 and 7x118=826.
So we have 2 - 34/63
21. Which of the following reductions is wrong ?

a) 55/35 = (55:5)/(35:5) = 11/7
b) 48/44 = (48:4)/(44:4) = 12/11
c) 81/108 = (81:9)/108:9) = 9/11
d) 54/63 = (54:9)/(63:9) = 6/7
11x9 = 99 not 108 .
y
22. What is the sum of the A values for which the expression in the figure below is not well defined ?

!


In case of need for tips get the cursor on "y" or for help click at "ry1/2".

RY1 RY2



a) 1 3/7
b) 2 1/3
c) 3 1/5
d) 4 3/8


1 + 4/3 = ? (Have a look at ry1) .
23. Which of the followings gives the minimal result ?

a) 3 2/7 - 2
b) 2 5/7 - 1
c) 3 6/7 - 3
d) 21/7 - 3
Choice d is 0 .
24. (3 1/3 + 1) - (3 + 1 1/6) = ?

a) 2/3
b) 3/4
c) 2/5
d) 1/3
(3+1-3-1) + (1/3-1/6) .
25. 1/1000 - 1/10000 = ?

a) 9/10000
b) 99/10000
c) 999/100000
d) 9999/100000
The first fraction is 10/10000 .
This is the feedback!

THANK YOU FOR YOUR VISIT; HOPE WE COULD BE OF USE.
FOR MUTUAL BENEFIT YOU MAY USE OUR FORUM.
© 2011 , Ä°smail GERMAN. ALL RIGHTS RESERVED
PLEASE PREFER GIVING LINK IF THAT SUFFICES

Share |


  
=> test-dr.com
  Logout
   Login


Test-Dr.com
GOOD SITE





Test-Dr.com
USEFUL SITE

VoltRank: Link Exchange