In the service of student community since Feb 2006
Hand Written NCERT Solutions
CBSE Sample Papers
CBSE Mock Tests
11 Years of Devotion in Maths
Absolutely Free

CBSE, CBSE Sample Papers, NCERT Solutions, CBSE Results,Math      

CCBSE, CBSE Sample Papers IX X, NCERT Solutions, CBSE Results 2016, Mathematics Concepts, CBSE Mock Tests, CBSE Syllabus, CBSE Date Sheets Previous Years Papers

Answers to Your Questions - Page 11
What do you get on this web page?
Here you get answers of your CBSE mathematics 1X and X questions by our experienced teachers. To ask a question click here
See Answers to Your questions
Question.110. A cylinder, cone, and hemisphere have same base and same height. find the ratio in their volumes? by siddharth 
Choudhary. Answered on Dec 24, 2007 at 1 : 40 p.m.Answer 110. The three are on same base so they have equal radii. Let each be x. They have equal height and height of hemisphere = radius. So height of each = radius = x. Required ratio = pie r^2 h : 1/3 pie r^2 h : 2/3 pie r^3
                                                                          =  r^2 h : 1/3 r^2 h : 2/3 r^3
                                                                          =  x^3 : 1/3 x^3 : 2/3 x^3
                                                                          = 1 : 1/3 : 2/3
                                                                          = 3 : 1 : 2
Question 111. Sir,usually i used to finish the exam in time,but this preboard i was not able to do so. So which section is to be answered first? Will just answers be sufficient for 1mark questions? by Sowmya. Answered on Dec 25, 2007 at 8:10 p.m.
Answer 111. (a) In our opinion you should begin with question no. 1 and try to do the questions in order if possible.     (b) 1 mark questions have to be answered in word, one sentence or as requirement of the question. For example if you consider the 5th question of 1st Model sample paper issued by CBSE in my opinion showing calculation is must. These papers can be downloaded from here
Question 112. A river 3m deep and 10 m wide is flowing at the rate of 2km per hour.how much water will fall into the sea in a minute? by Shalu. Answered on Dec 27, 2007 at 12:54 p.m. I.S.T.
Answer 112. Distance travelled by water in 1 hour = 2 km
                                                                       = 2000 m
Distance travelled by water in 1 min. = 2000/60
                                                                      = 100/3 m.
                     The river mentioned has shape of a cuboid when filled with water.
                     Volume of water falling in the sea in one minute = 100/3  ×  10  ×  3
                                                                                     = 1000 cu. m
                                                                                     = 1000 kl.  water.
                     Volume of water falling in the sea in one minute = 100/3  ×  10  ×  3
                                                                                     = 1000 cu. m
                                                                                     = 1000 kl.
See Answers to Your questions
Question 113. A container shaped like a right circular cylinder having diameter 12cm and height 15cm is full of ice-cream.The ice-cream is to be filled into cones of height 12cm and diameter 6cm having a hemispherical shape on the top.Find the number of such cones which can be filled with ice-cream, by Saumya Jain. Answered on Jan 03, 2007 at 10:26 p.m.
Answer 113. Volume of cylinder = pie r^2 h 
                                              = pie × 6 × 6×15
                                              = 540 pie cu. cm.
                     Volume of one ice cream cone including top = 1/3 pie r^2 h + 2/3 pie r^3

                                                                               = 1/3 pie r^2 (h + 2r)
                                                                               = 1/3 pie×3×3 (12 + 6)
                                                                               = 3 pie × 18
                                                                               = 54 pie cu. cm
                     No. of cones = Volume of cylinder/ volume of one cone including top = 540 pie/ 54 pie 
                                                                                                                 = 10
Question 114. A coin is tossed once.  Find probability of  getting  2 heads?  Jessika . Answered  on  Jan 4, 2008 at 10:18 pm IST
Answer 114.  When a coin is tossed we may get either a head or a tail.
                       Therefore total outcomes = 2
                        Favorable outcomes  = 0 (since we can have 1 head or 1 tail and never 2 heads in this case)
                        required  probability  =  0/2  
                                                    =  0
Question 115.  Determine whether the given quadratic equation has roots. If so find the roots of p(x) = 1/x+1 + 2/x+2 = 4/x+4   ( x is not equal to -1, -2, -4)  by  Himanshu Zharbade. Answered on Jan 5, 2007 at 9:05 p.m. I.S.T.
Answer 115. Download Now 
Question 116. the sum of p terms of an AP is q and sum of q terms is p.then prove that the sum of (p+q)terms is -(p+q) by ashwin kurian philip. Answered on Jan 6, 2007 at 6:24 p.m. I.S.T.      
Answer 116. Let first term = a
                     Common difference = d
                     Sp = q
                     p/2 [2a + (p-1)d] = q
                        p [2a + (p-1)d] = 2q
                           2ap + pd(p-1)  = 2q  ...........(i)
                     Sq = p
                     q/2 [2a + (q-1)d] = p
                      q   [2a + (q-1)d] = 2p
                           2aq + qd(q-1)  = 2p  ...........(ii)
                          (i) - (ii)
                      2ap - 2aq + pd(p-1) - qd(q-1) = 2q - 2p
                      2a(p - q) + d( p^2 - p - q^2 + q) = 2 (q - p)
                      2a(p - q)  + d(p^2 - q^2 + q - p) = 2 (q - p)
                      2a(p - q)  + d[(p-q) (p+q) + (q - p)] = 2 (q - p)
                      2a(p - q)  + d (p-q) [(p+q) - 1] = 2 (q - p) 
                      2a + d [(p+q) - 1] = - 2        (dividing both sides by p-q)
                      2a + d (p+q - 1) = - 2  ...........(iii)
                      S(p+q) = (p+q)/2 [2a + (p+q-1)d]
                                = (p+q)/2 (-2 )
                                =  - (p+q)  
                                   See Answers to Your questions
Question 117. If cos A= 2 sin A, then what will be the value of cosec A? by Shubham Jindal. Answered on Jan 08, 2007 at 9:44 p.m.
Answer 117.   cos A= 2 sin A
                   or  cosA/sinA = 2
                   or  cot A = 2
                   or  cot^2 A = 4
                   or cosec^2 A - 1 = 4    [ since 1 + cot^2 A = cosec^2 A] 
                   or cosec^2 A = 5
                   or cosec A = +- squareroot 5
Question 118. Please let me have some sample papers (chapter wise) for History & Civics for class X.  The cbsemath.com has only chapterwise for Geo, Eco and disaster Management by Noufel Arif. Answered on Jan 09, 2007 at 8:20 p.m. I.S.T.   
Answer 118. Sample papers of History, Civics and remaining chapters of geography will be added soon. We hope to add them in this month itself. 
Question 119. Find the sum of first 40 integers divisible by 6, by Saiyam. Answered on Jan 12, 2007 at 6:17 p.m.
Answer 119. First integers divisible by six are 6, 12, 18, 24,...     
                     Here a = 6 and d = 12 - 6 = 6
                     S40 = 40/2 [ 2×6 + 39×6]  
                           = 20[6(2+39)]
                           = 20[6×41]     
                           = 20×246
                           = 4920
Demo: Explicit load of a +1 button