1. which of the following is not a perfect square ? a) 1,00,856 b) 3,25,137 c) 9,45,729 d) all of these e) none of these
i am here taking only question 1...and explaning concept related to this....because i think this will help you a lot... perfect square- 1.)any number ending with 2,3,7,8 or odd numbers of zeros can't be perfect square 2.)a number which when divided by 4 leaves reminder 2/3 -when divided by 3 leaves reminder 2 -when divided by leaves reminder 2/3 can never be a perfect square. 3.)world's all perfect squares last digits has to be from this group- 00,01,04,09,16,25,21,24,29,36,41,44,49,56,61,64,69,76,81,84,89,96
always remember these properties while finding perfect square....
2. If 2 3.A test has 80 questions. There is one mark for a correct answer, while there is a negitive penalty of - 1/2 for a wrong answer and - 1/4 for an unattempted question. what is the number of questions answered correctly if the student has scored a total of 34.5 marks .
4. In above question 3 , if it is known that he has left 10 questions unanswered, the number of correct answers are ?
2.)i am not sure.... take X=3.9 and Y=2.9 X+Y=3.9+2.9 and X-Y=1 solve them you will get the answer...
3.)let,X=correct question Y=wrong question Z= unanswered questions X+Y+Z=80 X-(1/2)Y-(1/4)Z=34.50 solve both the equations you will get your answer...
4.)here just set Z=10...and then solve both the equations....
hello! i needed help with a pattern in number system. the question types are: 1)find the maximum value of n such that 50! is perfectly divisible by 2520^n? here the largest prime factor(i.e 7) was taken as restricting factor.. 2)) find the maximum value of n such that 50! is perfectly divisible by 12600^n? here instead of the biggest prime no.(i.e 7), 3 was taken as restricting prime factor. so, can somebody plz help me with this concept? i know that the longer way would be to calculate it for all the prime factors and see which one will be the smallest...but thus can be really lengthy (like in case of 504^n if we take 2 as the prime factor).. so can sumbody plz tell dat how is the limiting factor considered? thanks..
hello! i needed help with a pattern in number system. the question types are: 1)find the maximum value of n such that 50! is perfectly divisible by 2520^n? here the largest prime factor(i.e 7) was taken as restricting factor..
is answer of 1st question is 8???????/ either n=8 i am not sure::|:
hello! i needed help with a pattern in number system. the question types are: 1)find the maximum value of n such that 50! is perfectly divisible by 2520^n? here the largest prime factor(i.e 7) was taken as restricting factor..
hi... here we will consider 7...because it will have the lowest power.... just go for the long method for once it will help you clearing your doubt 2520=2^3*5*7*3^2 here we will have ample number of 2 and 3 in 50! hence the only one in which we will have confusion is 5 or 7...but after further solving you will find only deciding prime factor will be 7
anushri17 Says
yes the answer is 8... but i m still confused about which prime factor to consider...:(:(
1. which of the following is not a perfect square ? a) 1,00,856 b) 3,25,137 c) 9,45,729 d) all of these e) none of these
2. If 2 3.A test has 80 questions. There is one mark for a correct answer, while there is a negitive penalty of - 1/2 for a wrong answer and - 1/4 for an unattempted question. what is the number of questions answered correctly if the student has scored a total of 34.5 marks .
4. In above question 3 , if it is known that he has left 10 questions unanswered, the number of correct answers are ?
Q3) let x=correct, y=incorrect, z= unattended. so x+y+z = 80 and x*1+y*(-1/2)+z*(-1/4)=34.5 so this is a case of simple equation substitute the value of z which is in terms of x any y in second equation so u will get an equation in terms of x and y, now u need to keep on substituting the values so you will get a set of values. and for Q4) if z=10 u will get a definite solution so on substituting z=10 solving equations no. of correct answers (x) = 48
is answer of 1st question is 8???????/ either n=8 i am not sure:::
|anushri17 Says
yes the answer is 8... but i m still confused about which prime factor to consider...:(:(
but in 2nd question 3 becomes the limiting factor..so is there no fixed trait of the constraining factor?
for first the ans is 8 bt for 2nd also ans shud b 8 as we consider 7 ... why are we considering 3 as we have enough no. is 3's in this... limiting factor should b 7 ???? but it doesnt give the ans ...its the question from arun sharma n i also got struck here
if u need to find the power of a number in a factorial, u need to follow the below procedure where we use greatest integer no. denoted by
so if u need to find the power of 3 in 58! and 38! , u can do like this
+ + ++... which is equal to + + = 19+6+2 =27. if u will see after 3^4 in denominator ,rest of the values will be less than 1 so which will become 0. similarly u can try for finding the power of 3 in 38!
A rifle and a pistol were sold for Rs564,making a profit of 25% on the rifle and a profit of 20% on the pistol.By selling the rifle and the pistol for Rs563,the profit would be 20% on the rifle and 25% on the pistol.Find the ratio of difference and the sum of the cost prices of the rifle and the pistol.
1)1/11 2)1/19 3)1/23 pls suggest a shortcut for this problem.
A rifle and a pistol were sold for Rs564,making a profit of 25% on the rifle and a profit of 20% on the pistol.By selling the rifle and the pistol for Rs563,the profit would be 20% on the rifle and 25% on the pistol.Find the ratio of difference and the sum of the cost prices of the rifle and the pistol.
1)1/11 2)1/19 3)1/23 pls suggest a shortcut for this problem.
A rifle and a pistol were sold for Rs564,making a profit of 25% on the rifle and a profit of 20% on the pistol.By selling the rifle and the pistol for Rs563,the profit would be 20% on the rifle and 25% on the pistol.Find the ratio of difference and the sum of the cost prices of the rifle and the pistol.
1)1/11 2)1/19 3)1/23 pls suggest a shortcut for this problem.
my take is option 3 and rahul bhai just make 2 equations solve them you will get your answer 1.25X+1.20Y=564 1.20X+1.25Y=563 once subtract both the equations then you will get X-Y and and then add both the equations that will give you X+Y and that will solve your purpose
How many different 7 digit numbers are there the sum of whose digits are odd?
Did it with all distinct no. even no. should be even times, odd no. should be odd no. of times. 1)if 0 is taken into account 0,2,4,6,8....even 1,3,5,7,9....odd (7! - 6! )(5c1*5c5+5c3*5c3) 2) when 0 not there 7! (4c25c5) so (7! - 6! )(5c1*5c5+5c3*5c3) + 7! (4c25c5) Although I am not sure.
A rifle and a pistol were sold for Rs564,making a profit of 25% on the rifle and a profit of 20% on the pistol.By selling the rifle and the pistol for Rs563,the profit would be 20% on the rifle and 25% on the pistol.Find the ratio of difference and the sum of the cost prices of the rifle and the pistol.
1)1/11 2)1/19 3)1/23 pls suggest a shortcut for this problem.
After offering P% discount on marked price,the trader makes P% profit.If he offers only (P-10)% discount on marked price,he makes (P+15)% profit.Find the percentage by which the marked price exceeds the cost price.
a)20% b)30% c)35% d)40% e)50% pls do show the entire process.
100............120.......144 144............129.6.........96 144-96/96*100 =50% Although I am feeling wrong in some basics, but I am getting the answer.
X+Y=3.9+2.9 and X-Y=1