@cadmium said:Q.21 mango trees , 42 apple trees and 56 orange trees are to be planted in rows such that each row contains the same number of trees of one variety only. Minimum number of rows in which above trees can be planted is ?
17 😃
@negiSannu said:Find the number of consecutive zeroes immediately after the decimal in 1/(20^37)(log 2 = 0.3010)approach please?
a=20 ^-37 applyng log ==> a= -37 log20 ===> a= -37 (log10 +log2 ) = -37* 1.3010 = -48.XX = 48 zeros :)
The greatest number of four digits which is divisible by each one of the numbers 12,18,21 & 28, is ?
A. 9848
B. 9864
C. 9828
D. 9636
Concept and logical explanation please.
@cadmium said:The greatest number of four digits which is divisible by each one of the numbers 12,18,21 & 28, is ?A. 9848B. 9864C. 9828D. 9636Concept and logical explanation please.
LCM ( 12,18,21,28 )* N = 252 *N ==> "take a case 250*40 =10000 " so N here can accpt a max value of 39 to get highest 4 digt num so ans = 252*39 = 9828
@cadmium said:Q.21 mango trees , 42 apple trees and 56 orange trees are to be planted in rows such that each row contains the same number of trees of one variety only. Minimum number of rows in which above trees can be planted is ?
hcf of 21,42 and 56 is 7. total no of trees is 119. no of rows is 17
@cadmium said:The greatest number of four digits which is divisible by each one of the numbers 12,18,21 & 28, is ?A. 9848B. 9864C. 9828D. 9636Concept and logical explanation please.
the lcm of 12,18,21 and 28 is 252. check from the options whichever is divisible by it. the answer is 9828
Find the infinite sum of the series 1/1+1/3+1/6+1/10+1/15........
I know that in these types of question one can get an answer using options but can some1 please tell me the method!!
@sails said:Find the infinite sum of the series 1/1+1/3+1/6+1/10+1/15........I know that in these types of question one can get an answer using options but can some1 please tell me the method!!
2*(1-1/2) + 2*(1/2 - 1/3) + 2*(1/3 - 1/4) + ...
= 2*(1)
=2
= 2*(1)
=2
@sails
Should be 2..
Given, S= 1 + 1/3 + 1/6 + 1/10 + 1/15+.......Infinity
=>S = 2(1 - 1/2) + 2(1/2 - 1/3) + 2(1/3 - 1/4) + 2(1/4 - 1/5)+.....Infinity
=>S= 2[1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + 1/4 +.......Infinity]
=>S = 2..
@sails said:Find the infinite sum of the series 1/1+1/3+1/6+1/10+1/15........I know that in these types of question one can get an answer using options but can some1 please tell me the method!!
1/1+1/3+1/6+1/10+1/15.....
=2/1*2+2/2*3+2/3*4+2/4*5+2/5*6
=2(1-1/2)+2(1/2-1/3)+2(1/3-1/4)+....
=2(1)
=2
@all thanks..:) but does it just strike you like that ? or is it on practise..?
@sails said:@all thanks.. but does it just strike you like that ? or is it on practise..?
Mostly comes with practise bro. these are standard type problems..they dont change much
A man lends 9000 at r rate of interest for the first year. Next year he doubles it and in the third year he triples it and so on. If he gets back 15000 after a period of three years, what is the rate of interest in the first year.
options - 9%, 9.09%, 10%, 11.11% 12.5%
can I have a less calculation intensive method? thanks.
@sails said:Find the infinite sum of the series 1/1+1/3+1/6+1/10+1/15........I know that in these types of question one can get an answer using options but can some1 please tell me the method!!
2* [ 1/2 + 1/6 + 1/12 + 1/20 +...] = 2* [ 1/2 + 1/2 - 1/3+ 1/3 - 1/4 + 1/4 - 1/5 +.......] = 2 *1 =2
@veertamizhan said:A man lends 9000 at r rate of interest for the first year. Next year he doubles it and in the third year he triples it and so on. If he gets back 15000 after a period of three years, what is the rate of interest in the first year.options - 9%, 9.09%, 10%, 11.11% 12.5%can I have a less calculation intensive method? thanks.
here s.i = 15,000 -9000 =6000 ; ==> 6000 = 9000 [ 1*r+1*2r+1*3r]/100 ==> 2/3 = 6r ==> r=1/9 rate of intrst = 100/9 =11.11 %
@nramachandran said:Mostly comes with practise bro. these are standard type problems..they dont change much
thanks a lot...really heartbroken after my CAT'12 debacle..:(
@veertamizhan 11.11%
si is proportional to rate...rest all is same..so just equate simple interest(known and unknown)
Known is 15000-9000=6000
unknown is 90r+180r+270r=540r
r=6000/540=11.11%
si is proportional to rate...rest all is same..so just equate simple interest(known and unknown)
Known is 15000-9000=6000
unknown is 90r+180r+270r=540r
r=6000/540=11.11%
@veertamizhan
Given, Principal= 9,000 n Amt = 15,000...Thus, Interest= 6000
Now, 6,000 = 9,000(r/100 + 2r/100 +3r/100)
Thus, r = 100/9, or, Rate of Interest for the 1st year is 11.11%..
is there any method of recieveing a mail every time a new question is posted here...if yes then please tell me how..