3. What is a percent of b divided by b percent of a?

Let x be a percent of b: x=a/b
Let y be b percent of a: y=b/a

Find x/y

x/y=(a/b)/(b/a)=(a/b)^2

4. Perimeter of the back wheel = 9 feet, front wheel = 7 feet on a certain distance, the front wheel gets 10 revolutions more than the back wheel. What is the distance?

315 feet..

since front wheel takes 10 more revolutions so it travels 70 feet in those extra number of revolutions.
But distance travelled by front wheel is less by 2 feet as compared to rear wheel for each revolution. So this loss of 2 feet is covered by those extra revolutions taken by the front wheel.
So a deficit of 70 feet would have been created by 70/2=35 revolutions.
So rear wheel travels 35 revolution (and front wheel takes 35+10=45 Revs.) So distance is 35*9 (or 45*7) = 315 feet

11. If the 3 digit number AB9 is a perfect square then is A an odd digit?

AB9is a perfect square.Hence unit digit of the number must be 3 or 7.Since the perfect square is a 3 digit number the numbers can be either 13,17,23,27.....the perfect squares of these numbers are 169,289,529,729..therefore its not essential that the digit 'A' must be an odd number.

13. A student divided a number by 2/3 when he required to multiply by 3/2. Calculate the percentage of error in his result?

0 %Explanation:Since 3x / 2 = x / (2 / 3).

Student actually wants
x*(3/2) = 3x/2

but he did
x/(2/3) = 3x/2

So, 0% of error in the result.

14. In objective test a correct ans score 4 marks and on a wrong ans 2 marks are subtracted, a student score 480 marks from 150 question. how many ans were correct?

130.

Let,x be the correct answer and y
So,x+y=150..........(1)
and 4x-2y=480........(2)
By solving (1)& (2),
x=130.
So, the 130 questions were correct answer(Ans).

15. What is the angle between the two hands of a clock when time is 8:30?

75(approx).

ans is 75 degree
explaination;
hour hand 12hr-360deg
8hr-?
(8*360)/12=240deg
again hour hand 60min-30deg
30min-?
(30*30)/60=15deg
so total hr hand=240+15=255deg

now min hand; 60min-360deg
30min-?
(30*360)/60=180deg
difference will b 255-180=75deg

16. If x=y=2z and xyz=256 then what is the value of x?

x=y=2z;
xyz=256
or,xy.2z=2.256=512
or,x.x.x=512
or,x^3=8^3
or,x=8(Ans).

17. A dishonest shopkeeper professes to sell pulses at the cost price, but he uses a false weight of 950gm. for a kg. His gain is____%.

5.3 %Explanation:He sells 950 grams of pulses and gains 50 grams.If he sells 100 grams of pulses then he will gain (50 / 950) *100 = 5.26.

5% [Explanation: He sells 950 grams of pulses and gains 50 grams. He is getting 50 grams of pulse on 1000 grams. I.e. 5 % (50 / 1000 = 5/100)]

18. If there are 1024*1280 pixels on a screen and each pixel can have around 16 million colors. Find the memory required for this?

4MB.

each pixel can store a color ..that is either of the Red ,Green or Blue [RGB] colors.so all these 3 colors are stored consecutively in 1024 * 1280 pixels to display 16million colors approx..then the total memory used would be 1024 *1280 *3 = 3932160 bytes = 4mb

19. How big will an angle of one and a half degree look through a glass that magnifies things three times?

1 1/2 degrees Explanation :
The magnifying glass cannot increase the magnitude of an angle..

20. If on an item a company gives 25% discount, they earn 25% profit. If they now give 10% discount then what is the profit percentage?

30%.

The Profit shall be 50%.
Consider the item price as Rs.10.
After 25% discount, the cost would be Rs 7.5
Company would be profiting 25% on original price. Hence original price is Rs 6. (25% of 6 is 1.5. So 1.5+6=7.5)
Now if discount is 10% , the cost of item would be Rs.9. Hence 50% profit (as Rs 9 is 1.5 times of 6)

21. Five boys were climbing a hill. J was following H. R was just ahead of G. K was between G & H. They were climbing up in a column. Who was the second?

G.Explanation:The order in which they are climbing is R - G - K - H - J.

Another order is also possible: (top)H-J-K-R-G (bottom). And another possibility is: (top)H-K-J-R-G(bottom). "K was between G&H" doesn't mean "only K was between G&H". Finally, there is no way to tell for sure if G,J or K was the second.

22. 7^101+18^101 is a multiple of
a.15
b.25
c.35
d.45?

"Clearly," Naveen Reddy is an idiot. 7^101 + 18^101 is not the same as 7*101 + 18*101

23. A contractor agreeing to finish a work in 150 days, employed 75 men each working 8 hours daily. After 90 days, only 2/7 of the work was completed. Increasing the number of men by ________ each working now for 10 hours daily, the work can be completed in time?

150 men.Explanation:One day?s work = 2 / (7 * 90)One hour?s work = 2 / (7 * 90 * 8)One man?s work = 2 / (7 * 90 * 8 * 75)The remaining work (5/7) has to be completed within 60 days, because thetotal number of days allotted for the project is 150 days.So we get the equation(2 * 10 * x * 60) / (7 * 90 * 8 * 75) = 5/7 where x is the number of menworking after the 90th day.We get x = 225Since we have 75 men already, it is enough to add only 150 men..

90*75*8 = 2/7(work)
now 5/7 th of work left..
so 60*(75+x)*10 =5/7(work)
x=no of workers..
devide the two equations..
x=150

24. Each side of a rectangle is increased by 100% .By what percentage does the areaincrease?

300%.

100% of l=l
new length = l+l= 2l
new width = b+b= 2b
old area = l*b
new area = 2l * 2b
= 4lb
therfore increase in area= 400%