14, జులై 2014, సోమవారం

Mallapragada's Mathematics - ( 7th Standard-5)

                                                
                                                   
                                                  
1.A + B +C = 30cm,  A + B = 20 Cm. Find B + c ?


2.If we add 10 to twice a number we get 50. Find the number


3.If we subtract 30 from three times a number, we get 100. Find 
the number.


4.Find a number which when multiplied by 8 and then reduced by 4 is equal to 64.


5. Sum of two numbers is 100.  If one exceeds the other b 5, find the numbers.


6.Sum of three consecutive integers is 27. Find the integers.


7.Find  x  length 5x+4 and breath x-4 of the rectangle if its perimeter is 72m.


8. After 20 year. Rama’s age will become four times that of he present age. Find he present age.


9.length of a rectangle exceeds its breadth by 5m. If the perimeter of the rectangle is 100m. Find its length and breadth.


10.Rama  Said “multiplying my number by 10 and adding 20 to it gives the same answer subtracting my number from 40.  Find Rama’s number.


11. A number is divided into two parts such that one part is 20 more than the other. if the two parts in the  ration 4: 5 Find the number and the two parts.  


12.A sum of Rs. 5000 is to be given in the from of 75 prizes.  If the  prize money is either Rs 100 or Rs. 25. Find the number of prizes of each type.


13. x0 + 2x0 + 3x0 = 180  Find three angles


14. I am a number Tell my identity Take me two times over and add a forty six To reach a century You still need five.


15.The teacher tells the class that the highest marks obtained by a student in her class is twice the lowest marks plus10.  The highest mark is 90.  What is the lowest mark?  






















Om Sri Ram                            Om Sri Ram                     Om Sri Ram 
                                                                                     


1.A + B +C = 30cm,  A + B = 20 Cm. Find B + c ?

Ans.  20 + c = 30, c= 30-20 = 10



2.If we add 10 to twice a number we get 50. Find the number

Ans. Let the number = x, The twice number = 2x

         An adding 1= = 2x + 10

By problem: 2x + 10 = 50,   2x = 40   There fore x = 20

         

3.If we subtract 30 from three times a number, we get 90. Find the number.

Ans. Let the number = x, Then The three times Number  = 3x

         On subtracting  30 = 3x – 30

          By problem: 3x – 30 =100,  3x = 90 – 30 = 60

           Ther fore x = 60/3 = 20



4.Find a number which when multiplied by 8 and then reduced by 4 is equal to 68.

Sol. Let the number = x, Then The multiply by 8 = 8x

       By problem: 8x – 4 =68,  8x = 68 +4 = 72, x = 72/8 =9

     5. Sum of two numbers is 100.  If one exceeds the other by 6, find the numbers.

Sol. Lat the one number be=x, Then the other number =x-6

       Sum of the numbers: x + x-6 = 2x - 6

        By problem: 2x – 6 = 100, 2x = 100 + 6=106, x= 53   



6.Sum of three consecutive integers is 27. Find the integers.

    Let the three integers be x, x+1, x+2

    By problem+ 3x + 3=27, 3x = 27 -3= 24    x= 8

     Therefore consecutiveintegers= 8,9,10



7.Find  x  length 5x+4 and breath x-4 of the rectangle if its perimeter is 72m.

Sol: P=2(L+B)= 2(5x + 4 + x – 4)=  12x

        By problem: 12x = 72 ,    x = 72/12 =6

 

8. After 18 year. Rama’s age will become four times that of he present age. Find he present age.

Let the present age of Rama be x years

After 18 years Rama’s age = 4x

By problem : x + 18 = 4x       There fore 3x = 18,  x= 6

 

9.langth of a rectangle exceeds its breadth by 5m. If the perimeter of the rectangle is 100m. Find its length and breadth.

Sol. Breath = x, length = x + 5

       P= 2 (l + b) = 2(x + 5 +X) , 4x + 10 =100

       There fore 4x = 90 x=90/4 =22.5



10.Rama  Said “multiplying my number by 10 and adding 20 to it gives the same answer subtracting my number from 40.  Find Rama’s number.

Sol. Let Rama’s number be x

       Multiplying  by 10 and adding 20 to that number = 1ox +20

       Subtracting that number 40 =40 –x

       By proble above two are equal

       i.e = 10x + 20 = 40 – x , 11x = 20, x = 20/11



11. A number is divided into two parts such that one part is 20 more than the other. if the two parts in the  ration 4: 5 Find the number and the two parts.  

Sol. Let one part be x, Then the other part = x + 20

        Ratio of these two parts= x + 20 : x  = 4 : 5

         X + 20 /x = 4/5, 5(x + 20)=4x, 5x + 100 = 4x, x = -100

  

12.A sum of Rs. 5000 is to be given in the from of 75 prizes.  If the  prize money is either Rs 100 or Rs. 25. Find the number of prizes of each type.

Sol. Let the number of Rs. 100 prizes be x

         The number of Rs. 25 prizes be = 75-x ,

          Value of the prizes = 100 x + (75-x)25 = 100x -25x+1875=0

          By problem:  75x +1875 = 5000

                                 :75x = 5000 – 1875 = 3125

                                      X = 3125/75 = 41.6

 

13. x0 + 2x0 + 3x0 = 180  Find three angles

      6x = 180, x = 180/6 = 30

     The  angles   300, 600, 900



14. I am a number Tell my identity Take me two times over and add a forty six To reach a century You still need five.

       Let the number be x

       Two times the number = 2x

      On adding 46 = 2x + 46

       BY problem: 2x + 46 = 100-5

       2x = 95-46= 49   x= 49/2 = 24.5

         

15.The teacher tells the class that the highest marks obtained by a student in her class is twice the lowest marks plus10.  The highest mark is 90.  What is the lowest mark? 

Let the lowest marks of the class = x

Twice least marks = 2x , on adding  2x + 10

By problem : 2x + 10 = 90, 2x = 80 ,  x = 40