21. 16 - 21 ÷ 7 x 6 + 3 = 31

1. 1. - and +

   
   
   

   2. + and x

   
   
   

   3. ÷ and +

   
   
   

   4. ÷ and x

   
   
   

   5. - and x

   
   
   

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1. View Hint View Answer Discuss in Forum

   Lets try all options one by one.

   Correct Option: B

   If we interchange of signs '+' and 'x', then the equation changes into
   16 - 21 ÷ 7 + 6 x 3 = 16 - 3 + 18 = 31

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22. 5 x 15 ÷ 7 - 20 + 4 = 77

1. 1. - and +

   
   
   

   2. x and ÷

   
   
   

   3. + and ÷

   
   
   

   4. + and x

   
   
   

   5. - and ÷

   
   
   

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1. View Hint View Answer Discuss in Forum

   Lets try all options one by one.

   Correct Option: C

   If we interchanges signs '+' and '÷', then the equation changes into
   5 x 15 + 7 - 20 ÷ 4 = 5 x 15 + 7 - 5 = 77

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23. 4 x 2 + 6 ÷ 2 - 12 = 2

1. 1. ÷ and x

   
   
   

   2. + and -

   
   
   

   3. x and +

   
   
   

   4. ÷ and -

   
   
   

   5. x and -

   
   
   

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1. View Hint View Answer Discuss in Forum

   Lets try all options one by one.

   Correct Option: A

   If we interchanges signs '÷' and 'x', then the equation changes into
   4 ÷ 2 + 6 x 2 - 12 = 2 + 12 - 12 - 2

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24. 3 - 9 x 27 + 9 ÷ 3 = 3

1. 1. + and -

   
   
   

   2. x and +

   
   
   

   3. x and ÷

   
   
   

   4. - and ÷

   
   
   

   5. x and -

   
   
   

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1. View Hint View Answer Discuss in Forum

   Lets try all options one by one.

   Correct Option: E

   If we interchange 'x' and '-' , the equation changes into
   3 x 9 - 27 + 9 ÷ 3 = 27 - 27 + 3 = 3

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25. if 'R' means '÷', 'Q' means 'x', 'P' means '+', then 1 8 R 9 P 2 Q 8 = ?

1. 1. 18

   
   
   

   2. 16

   
   
   

   3. 28

   
   
   

   4. 30

   
   
   

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1. View Hint View Answer Discuss in Forum

   Using the correct symbols, we have
   1 8 R 9 P 2 Q 8
   = 18 ÷ 9 + 2 x 8
   

   Correct Option: A

   Using the correct symbols, we have
   1 8 R 9 P 2 Q 8
   = 18 ÷ 9 + 2 x 8
   = 2 + 2 x 8 = 2 + 16 = 18

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