CBSE Sample Papers for Class 12 Maths Solved 2018 Set 4
SECTION-A
Question numbers 1 to 6 carry 1 mark each.
SECTION-B
Question numbers 7 to 19 carry 4 marks each.
16.Two schools A and B decided to award prizes to their students for three values—honesty (x), punctuality y and obedience School A decided to award a total of Rs 11000 for three values to 5, 4, 3 students respectively and school B decided to award a total of Rs 10700 for three values to 4, 3 and 5 students respectively. If all together, it amounts to Rs 21700 then
i)Represent this by matrix equation and form linear equation using matrix multiplication.
ii)Is it possible to solve so obtained equations using matrices ?
iii)Which value you prefer to be rewarded ?
Or
18.There are two bags I and II, bag I contains 2 white and 3 red balls and bag II contains 4 white and 5 red balls. One ball is drawn at random from one of the bag and is found to be red. Find the probability that it was drawn from bag II.
SECTION — C
Question numbers 20 to 26 carry 6 marks each.
20. Give example of relations which are :
i)Symmetric but neither reflexive nor transitive.
ii)Transitive but neither reflexive nor symmetric.
iii)Reflexive and symmetric but not transitive.
iv)Reflexive and transitive but not symmetric.
v)Symmetric and transitive but not reflexive.
23.Using integration, find the area lying above x-axis and included between the circle x2 + y2 = 8x and the parabola y2 =4x
24.In a game, a man wins rupees five for a six and loses rupee one for any other number, when a fair die is thrown. The man dicided to throw a die thrice but to quit as and when he gets a six. Find the expected value of the amount he wins/loses.
25.Find the co-ordinates of the image of the point (1,3,4) in the plane 2x-y + z + 3 = 0.
26. Reshma wishes to mix two types of food P and Q in such a way that the vitamin contents of the mixture contains atleast 8 units of vitamin A and 11 units of vitamin B. Food P costs Rs 60/kg and food Q costs Rs 80/kg. Food P contains 3 units/kg of vitamin A and 5 units of vitamin B, while food Q contains 4 units/ kg of vitamin A and 2 units/kg of vitamin B. Determine the minimum cost of the mixture.
ANSWERS
SECTION-A
Question numbers 1 to 6 carry 1 mark each.
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SECTION-B
Question numbers 7 to 19 carry 4 marks each.
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16.Two schools A and B decided to award prizes to their students for three values—honesty (x), punctuality y and obedience School A decided to award a total of Rs 11000 for three values to 5, 4, 3 students respectively and school B decided to award a total of Rs 10700 for three values to 4, 3 and 5 students respectively. If all together, it amounts to Rs 21700 then
i)Represent this by matrix equation and form linear equation using matrix multiplication.
ii)Is it possible to solve so obtained equations using matrices ?
iii)Which value you prefer to be rewarded ?
Or
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18.There are two bags I and II, bag I contains 2 white and 3 red balls and bag II contains 4 white and 5 red balls. One ball is drawn at random from one of the bag and is found to be red. Find the probability that it was drawn from bag II.
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SECTION — C
Question numbers 20 to 26 carry 6 marks each.
20. Give example of relations which are :
i)Symmetric but neither reflexive nor transitive.
ii)Transitive but neither reflexive nor symmetric.
iii)Reflexive and symmetric but not transitive.
iv)Reflexive and transitive but not symmetric.
v)Symmetric and transitive but not reflexive.
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23.Using integration, find the area lying above x-axis and included between the circle x2 + y2 = 8x and the parabola y2 =4x
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24.In a game, a man wins rupees five for a six and loses rupee one for any other number, when a fair die is thrown. The man dicided to throw a die thrice but to quit as and when he gets a six. Find the expected value of the amount he wins/loses.
Ans.
25.Find the co-ordinates of the image of the point (1,3,4) in the plane 2x-y + z + 3 = 0.
Ans.
26. Reshma wishes to mix two types of food P and Q in such a way that the vitamin contents of the mixture contains atleast 8 units of vitamin A and 11 units of vitamin B. Food P costs Rs 60/kg and food Q costs Rs 80/kg. Food P contains 3 units/kg of vitamin A and 5 units of vitamin B, while food Q contains 4 units/ kg of vitamin A and 2 units/kg of vitamin B. Determine the minimum cost of the mixture.
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