bb wrote:
What to Memorize in GMAT Quant for the GMAT
There are a few things you can memorize for GMAT Quant that will help you answer questions faster, minimize mistakes, and fill in any gaps and holes.
This post collects the best tips from GMAT Club with special credit going to
einstein10.
Attachment:
Arithmetic Fractions and Percentages.pdf
Attachment:
what_to_remember_gmat_Q.pdf
Also some fun rules for not memorizing:
Multiples of 11If you need to multiply any two-digits number by 11, just sum those digits and put the result in between. For example,
13x11 -> 1+3=4 -> 143 is the result.
Or, 36x11 -> 3+6=9 -> the result is 36x11=396.
For 3 digits
133x11 --> 1 1+3 3+3 3=1463
And for 4 digits
1243x11 --> 1 1+2 2+4 4+3 3=13673
And for 5 digits
15453x11 --> 1 1+5 5+4 4+5 5+3 3=169983
For Multiples of 25Multiplying For example: 65*65
1) Always write down 25 as this is always the last two digits of the result:
...25
2) Multiply (non-units digits) times (non-units digits + 1)
6 * (6+1) = 42
3) Combine:
4225
Have your own? Share them here!we ll here learn how to find sq root of large nos.
first we must know that square of any no. does not end with i.e(last digit of the squared no.) 2,3,7 & 8.
If Last digit of the square (LHS) then last digit of the of sq. root(RHS) or vice versa
1....................................1 or 9
4....................................2 or 8
9....................................3 or 7
6....................................4 or 6
5.................................... 5
0.....................................0
for eg. the sq root of a no. ending in 1 could be 9 or 1. sq.rt of 81 = 9 , and sq. rt of 1 = 1.
nows lets see how to find sq rt of 5184
so in the above example our last digit is 4(LHS) hence the last digit of our ans could be 2 or 8. (RHS).
secondly we know 5184 is between 4900 and 6400. so the sq. rt of both these nos. 70 and 80 respectively. so our ans lies between 70 and 80
that means it could be 72 or 78.
but as we look at our no. 5184 . It is more closer to 4900 than it is to 6400.
therefore our ans has to be 72.