Maths Olympiad Previous Year Paper Part 2 Class 7

 Everyday Mathematics

 36. Four different bells beep after every 20  minutes, 40 minutes, 1 hour 20 minutes  and 1 hour 40 minutes. If all bell rings  (beeped) together at 5:00 a.m., then they  will again beep together at  

A. 6: 00 p.m.                                                                B. 11: 40 a.m.  

C. 12: 00 noon                                                             D. 9: 00 p.m.  

Answer 36. (B)

                   L.C.M ( 20, 40 80 ,100) = 400 

                   so, all bell rings together 400 minutes 

                   i.e, 6 hour 40 minutes after 5:00 a.m  i.e, 11:40 a.m. 

37. A man purchased 700 eggs. He found that  20% of them were broken. How many eggs  were found broken?  

A. 20                                                                             B. 70  

C. 140                                                                           D. 35  

answer 37 (C) Number of eggs purchased = 700

                       number of eggs broken = 20% of 700 

                                                             = 20 / 100 * 700   

                                                             = 140

38. The dimensions of a garden are 45 m by  20 m. In the garden, there is a square  shaped water pond with side 8 m. Find  the area of garden not including the water  pond. 

 A. 714 m2                                                                  B. 640 m2  

C. 836 m2                                                                   D. 630 m2  

Answer 38 (C ) 

Area of garden not including the water pond = Area of garden - Area of water pond 

                                                                        = (45 * 20) - (8 * 8 ) 

                                                                        = 900 - 64 = 836 m2  

39. Three students Varun, Kartik and Sid wrote  a statement on a blackboard.  

Varun wrote, “Two rectangles are congruent,  if they have same perimeter”.  

Kartik wrote, “Two squares are congruent,  if they have same area”.  

Sid wrote, “Two circles are congruent, if  they have same diameter”.  

Who wrote the correct statement?  

A. Varun and Kartik                                                          B. Kartik and Sid  

C. Varun and Sid                                                               D. Varun, Kartik and Sid  

Ans 39 (B)

40. Every floor of a 96 storey skyscraper is  5 m high. If a balloon rises 3 m every second, then how long will it take for the  balloon to rise from 47th floor to 92nd floor?  

A. 140 secs                                                                       B. 3 mins  

C. 2 mins                                                                          D. 75 secs  

Ans 40. (D)

Number of floor from 47th to 92nd = 45 

Total height of 45 floor = 45 * 5 = 225 m 

Since, balloon rises 3m every second. 

so, time taken for balloon to rise from 47th floor to 92 floor =225/3 =75 secs

41. An NGO brought 145.6 kg of weight at ₹ 11 per kg and distributes it quality amongst 110 people. What was the cost of the quantity of wheat that each person got ?

A ₹ 14.56                                 B ₹ 18.50                  

C  ₹ 21.25                                D ₹ 25.60

answer 41 (A ) Cost of 1 kg of wheat = ₹ 11 

                         Cost of 145.6 kg of weight = ₹ 11 * 145.6 

                                                                     = ₹ 1601.60 

                         As we taste this is distributed amongst 110 people ,

                     So, cost of quantity of meal that each person got = 1610.60 /110 = ₹ 14.56

42. In an examination, a student was asked to find 5/ 17 of a certain number. By mistake he found 17/5 of that number. If his answer was 264 / 119 more than the correct answer, then find the number.

A   7/5                                        B   5/7  

C   3/7                                        D   7/3

Ans 42 (B)

     Let the number be x.

     so, correct answer = 5/17 * x = 5x/17

      Incorrect answer = 17/5 * x = 17x/5

     According to question, 17x/5 = 5x/17 + 264/119

                                           17x/5 = 35x + 264/119

                                           2023x = 175x + 1320

                                           1848x = 1320

                                             x = 1320/1848 = 5/7 

43. The average height of 6 employees of a company is 152 cm. When an employee leaves the company, the new average becomes 156 cm. Find the height of employee who left the company.

A   132 cm                                 B 138 cm

C    152 cm                                D 140 cm

Answer 43 (A ) Average height of 6 employees = 152 cm. 

              sum of height of 6 employees / 6 = 152

             sum of height of 6 employees  = 152 * 6 = 912 cm

           Let the height of employee who left the company be x cm.

               so, 912 - x/5 = 156

               912 - x = 780 

                      -x = 780 - 912

                       -x  = -132

                         x = 132cm

 44. Gaurav travelled (P² - 4P + 2) km by car and (2P² + 6P – 5) km by bus. What is the total distance travelled by Gaurav?

A    (P² +2P -3) km

B    (3P² -3P -3) km

C    (3P² + 2P -3) km

D    3(P²  - P - 2) km

Ans 44 (C) : Distance travelled by car = (P² - 4P + 2)km

                      Distance travelled by bus = (2P² + 6P – 5) km

                     Total distance travelled =  (P² - 4P + 2 + 2P² + 6P – 5) km

                                                            =  (3P² -3P -3) km            

45. A student has to score 40% of the maximum marks to pass. Ronak score 85 Marks and failed by 35 marks. Find the maximum mass.

A 450                          B 250

C 400                          D 300 

Answer 45 (D) : Let the maximum mark be x.

                        Number of marks score to pass = 40 % of x

                                                                           = 40x/100 = 2x/5

                   According to question , 2x/5 = 85 + 35

                                                         2x/5 = 120

                                                           x = 120 * 5/2

                                                           x = 300

46. Which of the following options represent the incorrect match of the given 3-D figures and their nets?

 

 Ans 46 (C)

47. Read the statement carefully and select the correct option. 

Statement -1: The line segment joining a vertex of a triangle to the midpoint of its opposite side called the median of the triangle. 

Statement - 2: If the exterior angle of the triangle is a right angle, then each opposite interior angle is an obtuse angle.

  A. Both Statement -1 and Statement 2 are true.

  B. Both Statement -1 and Statement -2 are false.

  C. Statement -1 is true but Statement- 2 is false.

  D. Statement -1 is false but statement- 2 is true

Ans 47 (C):

          Statement -1 is true

          Statement- 2 : If the exterior angle of a triangle is right angle, then sum of two interior opposite angles is 90° i.e. each of the opposite interior angle is acute. So, Statement 2 is false.

48 Read the given statement carefully and state T for true and F for false .

i) If the simple interest on the sum is equal to the principal and the number of year is equal to the rate percent per annum then the rate of interest is 10% per annum. 

ii) If a person purchases 12 items for ₹ 36 and sales 10 item for ₹ 36 then the profit percent is 15%.

iii) The percentage decreases in the price of shirt it decreases from rupees 4000 to rupees 2500 in 15%.

                  (i)          (ii)         (iii)

A               T           T              F

B               T           F              F

C               F           T              F

D              F            F             T

Ans 48 (B) : 

(i) True; 

Let Principle = ₹ P , Rate of interest = R% ; since SI = ₹ P; Time T = R

           so SI = PRT /100 

                 P = P*R*R/ 100 

                 R² =100 

                 R = 10%

(ii) False; 

Cost price of 12 items =  ₹ 36 

Cost price of 10 itoms = 36 / 12 * 10 = ₹30 

Selling price of 10 items = ₹ 36 so profit % = SP - CP /C.P * 100 = 36 - 30 / 30 *100 = 20% 

(iii) False; Percentage decreases = 4000 - 2500 / 4000 * 100 = 37.5%

49. Match the following and select the correct option.

 

Ans 49 (B) :

50. The runs scored by a player in 15 matches are as follows.

      55, 40, 38, 45, 52, 80, 85, 72, 90, 88, 76, 71, 65, 52, 66

     Find

     (a) Mean

     (b) Median

     (c) Mode

   (a)         (b)        (c)

A .   65        66         52

B.    60        66         50

C.    65        72         52

D.    60        68         45

Ans 50 (A):