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Home › Grade7 › Grade 7 Olympiad › Math Olympiad-Grade-7 › Calculations › Calculations Worksheet-3

Calculations Worksheet-3

Calculations Worksheet-3

 

  1. If x and y are negative, then which of the following statements is / are always true ?

I. x + y is positive, II. xy is positive,   III. x – y is positive

(a) I only            (b) II only          (c) III only         (d) I and III only

 

  1. If – 1 ≤ x ≤ 2 and 1 ≤ y ≤ 3, then least possible value of (2y – 3x) is :

(a) 0                    (b) – 3                (c) – 4                (d) – 5

 

  1. If a and b are both odd numbers, which of the following is an even number ?

(a) a + b             (b) a + b + 1      (c) ab                  (d) ab + 2

 

  1. Which of the following is always odd ?

(a) Sum of two odd numbers 

(b) Difference of two odd numbers

(c) Product of two odd numbers

(d) None of these

 

  1. For the integer n, if n3 is odd, then which of the following statements are true ?

I. n is odd, II. n2 is odd, III. n2 is even

(a) I only                                         (b) II only

(c) I and II only                             (d) I and III only

 

  1. The least prime number is :

(a) 0                    (b) 1                    (c) 2                    (d) 3

 

  1. What is the total number of prime numbers less than 70 ?

(a) 17                  (b) –18               (c) 19                  (d) 20

 

  1. The total number of even prime numbers is–:

(a) 0                    (b) 1                   (c) 2                    (d) None of these

 

  1. Find the sum of prime numbers lying between 60 and 75

(a) 199                (b) 201               (c) 211                 (d) 272

 

  1. The smallest three–digit prime number is :

(a) 103                (b) 107                (c) 109                (d) None of these

 

  1. Which one of the following is a prime number ?

(a) 161                (b) 221                (c) 373                (d) 437

 

  1. The smallest value of n, for which 2n + 1 is not a prime number, is :

(a) 3                    (b) 4                    (c) 5                    (d) None of these

 

  1. The sum of three prime numbers is 100. If one of them exceeds another by 36, then one of the numbers is :

(a) 7                    (b) 29                 (c) 41                  (d) 67

 

  1. There are four prime numbers written in ascending order. The product of the first three is 385 and that of the last three is 1001. The last number is :

(a) 11                   (b) 13                  (c) 1.7                 (d) 19

 

  1. How many numbers between 400 and 600 begin with or end with a digit of 5 ?

(a) 40                 (b) 100               (c) 110                (d) 120

 

  1. If we write all the whole numbers from 200 to 400, then how many of these contain the digit 7 once and only once ?

(a) 32                  (b) 34                 (c) 35                  (d) 36

 

Answer Key:

(1)-(b); (2)-(c); (3)-(a); (4)-(c); (5)-(c); (6)-(c); (7)-(c); (8)-(b); (9)-(d); (10)-(d); (11)-(c); (12)-(b); (13)-(d); (14)-(b); (15)-(c); (16)-(d)