10 second questions

Jai Ganesh · 2009-04-01 04:08:25

#1836. A hollow sphere of internal and external diameters 4 cm and 8 cm respectively is melted to form a cone of diameter 8 cm. What is the height of the cone?

#1837. 12 spheres of the same size are made from melting a solid cylinder of 16 cm diameter and 2 m height. What is the diameter of each sphere?

#1838. The surface area of a sphere is the same as the curved surface area of a right cirvcular cylinder whose height and diameter are 12 cm each. What is the radius of the sphere?

#1839. The volumes of two spheres are in the ratio 64:27. What is the ratio of their surface areas?

#1840. If three metallic spheres of radius 6 cm, 8 cm, and 10 cm are melted to form a single sphere, what would the diameter of the new sphere be?

#1841.A hollow metallic ball has an external diameter 6 cm and is ½ cm thick. What is the volume of the metal used in the ball?

#1842. A cylindrical vesselof radius 4 cm contains water. A sold sphere 3 cm is lowered into the water until it is completely immersed. By what level does the water in the vessel rise?

#1843. If the radius of a sphere is increased by 2 cm, then its surface area increases by 352 cm². What is the radius of the sphere before the increase?

#1844. Spheres A and B have their radii 40 cm and 10 cm respectively. What is the ratio of surface area of A to the surface area of B?

#1845. If the volume of a sphere i ivided by the surface area, the result is 27 cm. What is the radius of the sphere?

Jai Ganesh · 2009-04-01 17:20:07

#1846. Aboatman goes 2 km against the current of the stream in 1 hour and goes 1 km in 10 minutes with the current. How long would it take for him to go 5 km in still water?

#1847. A boat moving downstream covers a distance of 16 km in 2 hours while for covering the same distance upstream, it takes 4 hours. What is the speed of the boat in still water?

#1848. A man takes twice as long to row a distance against the stream as to row the same distance in the direction of the stream. What is teh ratio of the speed of the boat in still water to that of the stream?

#1849. A boat moving upstream takes 8 hours 48 minutes to cover a certain distance while it takes 4 hours to cover the same distance running downstream. What is the rato of the speed of the boat to taht of the water curent?

#1850. A boat can travel with a speed of 13 km/hour in still water. If the speed of the stream is 4 km/hour, find the time taken by the boat to travel 68 kilometers downstream.

#1851. If 405 of a number is equal to two-third of another number, what is the ratio of the first number to the second number?

#1852. A sum of money is to be distributed among A, B, C, and D in the proportion 5:2:4:3. If C gets $1000 more than D, how much does B get?

#1853. The ratio of the number of boys and girls in a college is 7:8. If the perentage increase in the number of boys and girls be 20% and 10% respectively, what would be the new ratio?

#1854. A and B together have $1210. If four-fifteenth of A's amount is equal to two-fifth of B's amount, how much amount does B have?

#1855. If p, q, r, and s are the shares of $1300 to be divided among P, Q, R, and S, and if

,
what is P's share?

Jai Ganesh · 2009-04-02 17:49:00

#1856. What is the term independent of x in the expansion of

?

#1857. What is the sum of coefficients in the expansion of

?

Jai Ganesh · 2009-04-02 21:38:38

#1858. Alfred buys an old car for $4700 and spent $800 on repairs. He sold the car for $5800. What is his profit percentage?

#1859. John buys a car for $1400 and sells it at a loss of 15%. What is the selling price of the car?

#1860. Peter purchased a machine for $80,000; spent $5,000 on repair and $1,000 on transport. He sold it at 25% profit. At what price did he sell the machine?

#1861. Jacob bough a motorcycle for a certain sum, he spent 10% of the cost on repairs an sold it for a profit of $1,100. How much did he spend on repairs if he made a profit of 20%?

#1862. A manufacturer undertakes to supply 2000 pieces of a particular component at $25 per piece. According to his estimate, even if 5% fail the quality tests, he'd make a profit of 25%. However, 50% of the components were rejected. What is the loss to the manufacturer?

#1863. When a plot is sold for $18,700, the owner loses 15%. At what price must the plot be sold so that the owner gains 15%?

#1864. A property dealer sells a house for $630,000 and in the bargain, makes a profit of 5%. What would have his profit or loss percentage been had he sold it for $500,000?

#1865. A dealer sells a music system for $840 at a gain of 20% and sells another for $960 at a loss of 4%. What is his total gain or loss percentage?

#1866. The ratio of the cost price and the selling price is 4:5. What is the profit percentage?

#1867. The ratio of the selling price and cost price of an article is 7:5. What is the ratio of the profit and the cost price of that article?

#1868. A trader gains 20% by selling an article for a certain price. What would his profit percentage be if he sold it for double the price?

#1869. If the selling price doubles, the profit triples. What is the profit percentage on the actual selling price?

#1870. The profit earned by selling an article for $832 is equal to the loss incurred by selling the same article for $448. What should be the selling price in order to make a profit of 50% on the sale?

Jai Ganesh · 2009-04-04 02:55:05

#1871. What is the value of

?

#1872. If a[sup]2x+2[/sup] = 1 where a is a positive real number other than 1, then what is the value of x?

#1873. If 3[sup]x+3[/sup] + 7 = 250, what is the value of x?

#1874. If

#1875. What is the value of x if

?

#1876.

,
then what is the value of
?

#1877. Which is the greatest among

?

Jai Ganesh · 2009-04-04 17:21:33

#1878. The salaries of Richard and Stuart are in the ratio 2:3. If the salary of each is increased by $4,000, the new ratio becomes 40:57. What is Stuart's salary before the increase?

#1879. If A:B:C = 2:3:4, then what is

equal to?

#1880. If A : B = 2 : 3, B : C = 4 : 5, and C : D = 6 : 7, then what is A : B: C : D equal to?

#1881. What is the value of x if

?

#1882. What is the value of x if 0.75:x::5:8?

#1883. If x:y = 5:2, then (8x+9y):(8x+2y) = ?

#1884. Two numbers are in the ratio 1:2. If 7 is added to both of them, their atio changes to 3:5. Which is the greater number?Find the fraction that bears the same ratio to

that
.

#1885. The ratio of earnings of A and B are in the ratio 4:7. If the earnings of A increases by 50% and that of B decreases by 25%, the new ratio of their earnings becomes 8:7. What are A's earnings?

Jai Ganesh · 2009-04-06 03:20:20

#1886. if the straight line 7x - 5y = k passes through the point (1,1), what is the value of k?

#1887. Find the equation of the straight line passing through (5,1) and (-2,2).

#1888. Find the equation of the straight line passing through the point (1,3) and parallel to the straight line 5x - 3y + 1 = 0.

#1889. Find the equation of the straight line whose slope is 4 and which passes through the point (5, -7).

#1890. Find the equation of the straight line parallel to the line joining the points (7,5) and (1,3) and passing through the point (-3, 4).

#1891. Find the equation of the straight line parallel to the x-axis and passing through the point
(-3,2).

#1892. Find the equation of the straight line whose inclination with the x-axis is 60° and which passes through the origin.

#1893. Find the equation of the straight line whose inclination is 30° with the x-axis and whose y-intercept is -3.

#1894. Find the equation of the straight line whose y-intercept is -4 and whose slope is

.

#1895. The equation of a straight line is 3x = 2y + 1 = 0. Find its slope and y-intercept.

Jai Ganesh · 2009-04-06 03:50:11

#1896. Find the sum to 8 terms of the Geometric progression 2, 4, 8, .....

#1897. Find the sum to infinity of the series 54, 18, 6, 2, ......

#1898. Express

as a fraction.

#1899. The first term of an infinite Geometric Progression is 6 and its sum is 8. Find the Geometric progression.

#1900. The sum of an infinite Geometric Progression is 4 and the sum of the cubes of the terms is 192. Find the common ratio.

Jai Ganesh · 2009-06-07 19:44:29

#1901. A book contains 400 pages in all. How many digits does it contain?

Jai Ganesh · 2009-06-07 23:46:43

#1902. Whats special about the aprroximate number 0.47712125471?

Jai Ganesh · 2009-06-07 23:48:40

#1903. How many times would the number zero appear in the fisrst 30 places after the decimal?

Jai Ganesh · 2009-06-07 23:58:41

#1904. How many prime numbers exist between 1 ad 100, both not inclusive?

bobbym · 2009-06-08 00:54:46

Hi ganesh;

#1902

Jai Ganesh · 2009-06-08 16:43:14

Remarkable!

#1905. Can an even palindrome number be a prime number?

#1906. How manyzeros does a Googolplex contain?

bobbym · 2009-06-11 07:50:17

#1906

Jai Ganesh · 2009-06-13 19:03:58

You think right, bobbym! Congratulations!!!

Jai Ganesh · 2009-06-13 19:06:14

#1907. Is the chance of a number of the form

more being prime or non-prime?

#1908. What is the value of 6 x 6 x 6 x 6 x 6?

bobbym · 2009-06-14 00:38:38

Last edited by bobbym (2009-06-14 02:29:47)

Jai Ganesh · 2009-06-14 17:05:00

#1907.
Please stand corrected. The nummbers of the form

are more often non-prfimes, either divisible by 11 or 101.

bobbym · 2009-06-14 17:11:04

Hi ganesh;

I thought they are more often non prime because 3/4 of them are divisible by 11 or 101, where am am I going wrong. Help please.

Last edited by bobbym (2009-06-14 17:11:35)

Jai Ganesh · 2009-06-14 23:23:11

I am sorry boobym, you were exactly right.

#1909. What is the value of a or b if 47a + 47b = 423?

bobbym · 2009-06-14 23:53:06

Divide 47a+47b= 423 by 47 to get a+b=9. Easy now to get all solutions:
.
.
.
a=0, b=9
a=1, b=8
a=2, b=7
a=3, b=6
a=4, b=5
a=5, b=4
a=6, b=3
a=7, b=2
a=8, b=1
a=9, b=0
.
.
.

Jai Ganesh · 2009-06-14 23:54:58

Excellent!!!

bobbym · 2009-06-15 19:22:37

Last edited by bobbym (2009-06-15 19:23:02)

Jai Ganesh · 2009-06-17 18:21:23

Answer to #1771:-
Outstanding, bobbym!!!

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