Oral puzzles

krassi_holmz · 2006-04-24 05:47:31

169. Find the samller of the two numbers whose sum is 35 and difference is 5.
x>y
x+y=35
x-y=5
x=y+5
2y+5=35
2y=30
y=15

krassi_holmz · 2006-04-24 05:51:13

168.
√(x+1)-√(x-1)=1.
x=5/4

krassi_holmz · 2006-04-24 05:52:39

167.
a=5.

krassi_holmz · 2006-04-24 05:53:41

166.
4x-2=6
x=2

krassi_holmz · 2006-04-24 05:55:53

165.
2

krassi_holmz · 2006-04-24 05:58:13

164.
x=2

krassi_holmz · 2006-04-24 05:59:45

163.
127.2deg

Patrick · 2006-04-24 06:01:43

krassi_holmz wrote:

175. Not sure I understand this one, but: y=11?
y can't be 11 because the remainder must be > of the divisor.

hehe, true.. But I was actually referring to 176.. You should have guessed that!

Last edited by Patrick (2006-04-24 06:02:01)

krassi_holmz · 2006-04-24 06:05:29

162.
θ=Pi/4
f(θ)=√2

krassi_holmz · 2006-04-24 06:09:20

161.
theta=0.5

krassi_holmz · 2006-04-24 06:11:01

Patrick wrote:

krassi_holmz wrote:
175. Not sure I understand this one, but: y=11?
y can't be 11 because the remainder must be > of the divisor.
hehe, true.. But I was actually referring to 176.. You should have guessed that!

yes

krassi_holmz · 2006-04-24 06:12:48

160.
x=4

Jai Ganesh · 2006-04-24 16:52:41

Neat job, krassi_holmz!
Most of your answers are correct!
163 and 171 are wrong!

Jai Ganesh · 2006-04-24 17:26:18

181. A policeman is running after a thief who is 200 metres ahead of him. The policeman runs at 4 1/6 meters per second and the thief at 2 1/3 metres per second. In what time will the thief be caught by the policeman?

182. A train 100 metres long crosses a man going in the opposite direction at the rate of 5 kilometers per hour and passes him in 7.2 seconds. What is the speed of the train?

183. Walking at 4 kilometers per hour, a clerk reaches his Office 8 minutes late. If he walks at the speed of 5 kilometers per hour, he would be 2 1/2 minutes early. What is the distance of his workplace from his house?

Jai Ganesh · 2006-04-24 20:39:49

184. If (sinx-cosx)²=0.5, what is the value of (sinx+cosx)²?

185. if p and q are the roots of the equation x²-7x+12=0, what is the value of p²+q²?

Jai Ganesh · 2006-04-25 20:09:25

186. If the first term of an Arithmetic Progression is 5 and the 100th term is -292, what is the 51st term?

187. How many terms are there in the Arithmetic Progression given below?
7, 13, 19, ..............., 97.

188. What is the value of 11²+12²+13²+.......20²?

189. If 1²+2²+3²+...10²=385, what is the value of 2²+4²+6²+....20²?

190. What is the value of

191. How many terms are there in the series 6, 18, 54, ....., 1458?

192. If two cylinders have their radii in the ratio 4:5 and their heights in the ratio 5:6, what is the ratio of their volumes?

193. A cone made of clay of height 24 cm and radius 6 cm is reshaped into a sphere. What would the radius of the sphere be?

194. If the area of cross section of a cylinder is 22 cm² and its height is 14 cm, what would be its volume?

195. The diameter of the base of two cones are equal. If their slant heights are in the ratio 5:4, what would the ratio of their curved surface areas be?

Jai Ganesh · 2006-04-26 16:32:38

196. What is the value of

?

197. If i,j and k are three mutually perpendicular unit vectors, what is the value of the scalar triple product

?

Jai Ganesh · 2006-04-26 17:57:11

198. For what value of k would the following system of equations have infinite solutions?

2x+3y=5
4x+ky=10

199. For what value of k would the following equations have no solution?
x+2y-3=0
5x+ky+7=0

200. For what value of k would the equations
2x+32y+3=0 and 3x+48y+k=0
represent coincident lines?

Jai Ganesh · 2006-04-27 15:07:54

201. If 40 persons consume 240 kilograms of rice in 15 days, in how many days would 30 persons consume 48 kilograms of rice?

202. Ten pipes of the same type fill a tank in 24 minutes. If two of the pipes are not working, how long would the remaining 8 pipes take to fill the tank?

203. If 22.5 meters of a uniform metal rod weighs 85.5 kilograms, what would be the weight of 9 meters of the same rod?

204. If 15 men can reap a field in 35 days, how many would 21 men require to reap the same field?

205. If 20 men working 7 hours a day can complete a work in 10 days, how many days would 15 men working 8 hours a day require to do the same work?

Jai Ganesh · 2006-04-27 15:18:45

206. Which is the highest number which the product of three consecutive natural numbers, the first of which is even, would be divisible by?

207. What would be the digit in the unit's place in the product

?

208. Which of the two is greater?

209. What is the value of the given expression?

210. If 146! is divisible by

, what is the maximum value of n?

Jai Ganesh · 2006-04-28 16:42:11

211. Which is the number which when added to itself 17times gives 162?

212. The sum of the squares of two numbers is 761. What is the sum of the numbers?

213. A fraction becomes 4 when 1 is added both to the numerator and the denominator. If 1 is subtracted from both the nuerator and the denominator, the fraction becomes 7. What is the numerator of the fraction?

214. A number eceeds its one seventh by 84. What is the number?

215. The sum of the squares of two numbers is 3341 and their difference is 891. Which is the smaller number?

216. Which is the smallest perfect square divisible by 3, 4, 5, 6, and 8?

217. 96% of the population of a town, 23040 people, are literate. What is the total population of the town?

218. What percent of 2/7 is 1/35?

219. In an examination, a candidate should score 36% in order to pass in the examination. A student scores 113 marks and fails by 85 marks. What is the maximum markes in the examination?

220. In a class, the number of boys is more than the number of girls by 12% of the total strength of the class. What is the ratio of the number of boys to the number of girls?

Jai Ganesh · 2006-04-30 01:50:32

221. The sum of the squares of three consecutive odd numbers is 251. Whch is the first number?

222. Of the three numbers, the first is twice the second and half of the third. If the average of the three numbers is 56, what is the greatest number?

223. A can do a work in 24 days. If B is 60% more efficient than A, how many days would B require to do the same work?

224. If

what is the value of x?

225. If

what is the value of x?

Jai Ganesh · 2006-04-30 15:58:28

226. Each interior angle of a regular polygon is 135°. How many sides does the polygon contain?

227. How many diagonals does a decagon contain?

228. Two circles touch externally. The sum of their areas is 130 pi square centimeters and the distance between the centers is 14 cm. What is the radius of the smaller circle?

229. Two circles touch internally. The sum of their areas is 116 pi square centimeters and the distance between their centersa is 6 cm. What is the radius of the larger circle?

230. If a regular hexagon is inscribed in a circle of radius r, what is the perimeter of the hexagon?

Jai Ganesh · 2006-05-02 02:59:27

231. If z=2+i√3, what is the value of

?

232. What is the value of

?

233. What is the value of

?

234. What is the value of

?

235. What is the value of

?

Jai Ganesh · 2006-05-02 16:06:45

236. A contractor undertook to complete a work in 60 days. He employed 200 men. In 36 days, only half the work was completed. How many more men should be employed to complete the work in time?

237. 20 men can complete a work in 40 days. hen should 4 men leave so that the work be finished in 48 days?

238. If m men can do a job in d days, in how many dyas would (m+r) men do the same job?

239. If x men can do a work in 8 days and (x+4)men can do the samw work in 6 days, what is the value of x?

240. A man spends in 3 months what he earns in 2 months. If he saves $1500 at the end of one year, what is his monthly income?

Math Is Fun Forum

#76 2006-04-24 05:47:31

Re: Oral puzzles

#77 2006-04-24 05:51:13

Re: Oral puzzles

#78 2006-04-24 05:52:39

Re: Oral puzzles

#79 2006-04-24 05:53:41

Re: Oral puzzles

#80 2006-04-24 05:55:53

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#81 2006-04-24 05:58:13

Re: Oral puzzles

#82 2006-04-24 05:59:45

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#83 2006-04-24 06:01:43

Re: Oral puzzles

#84 2006-04-24 06:05:29

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#85 2006-04-24 06:09:20

Re: Oral puzzles

#86 2006-04-24 06:11:01

Re: Oral puzzles

#87 2006-04-24 06:12:48

Re: Oral puzzles

#88 2006-04-24 16:52:41

Re: Oral puzzles

#89 2006-04-24 17:26:18

Re: Oral puzzles

#90 2006-04-24 20:39:49

Re: Oral puzzles

#91 2006-04-25 20:09:25

Re: Oral puzzles

#92 2006-04-26 16:32:38

Re: Oral puzzles

#93 2006-04-26 17:57:11

Re: Oral puzzles

#94 2006-04-27 15:07:54

Re: Oral puzzles

#95 2006-04-27 15:18:45

Re: Oral puzzles

#96 2006-04-28 16:42:11

Re: Oral puzzles

#97 2006-04-30 01:50:32

Re: Oral puzzles

#98 2006-04-30 15:58:28

Re: Oral puzzles

#99 2006-05-02 02:59:27

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#100 2006-05-02 16:06:45

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