## Mathematical operation and symbol notation

#### Mathematical operation and symbol notation

Direction: Correct the following equations by interchanging the two signs.

1. 15 ÷ 9 x 3 - 74 + 2 = 5
1. + and -
2. ÷ and x
3. + and ÷
4. - and ÷
5. None of the these

1. Lets try all options one by one.

##### Correct Option: C

If we interchanges signs '+' and '÷', then the equation changes into
15 + 9 x 3 - 74 ÷ 2 = 15 + 27 - 37 = 5

1. 51 ÷ 3 x 12 - 6 + 3 = 201
1. + and ÷
2. - and +
3. x and ÷
4. - and x
5. None of these

1. Lets try all options one by one.

##### Correct Option: E

None of the interchange is applicable in the equation to produce number 201

1. 16 + 4 ÷ 2 - 21 x 7 = 21
1. + and -
2. + and x
3. - and ÷
4. x and ÷
5. None of these

1. Lets try all options one by one.

##### Correct Option: D

If we interchange the signs 'x' and '÷' the equation becomes
16 + 4 x 2 - 21 ÷ 7 = 16 + 8 - 3 = 21

1. 32 x 2 2 ÷ (62 - 9) + 12 = 33
1. - and ÷
2. + and x
3. x and ÷
4. + and -

1. Lets try all options one by one.

##### Correct Option: A

If we interchange symbols '-' and '÷', the equation becomes
9 x 4 - (36 ÷ 9) + 1
= 9 x 4 - 36/9 + 1
= 36 - 4 + 1
= 33

Direction: In the following questions, which one of the four interchanges in signs and numbers would make the given equation correct?

1. 4 x 6 - 2 = 14
1. x to ÷, 2 and 4
2. - to +, 2 and 6
3. x to +, 4 and 8
4. - to ÷, 2 and 6

1. Interchange '-' to '+' and 2 to 6 and try

##### Correct Option: B

On interchanging '-' to '+' and 2 to 6
4 x 2 + 6 = 14
⇒ 8 + 6 = 14
⇒ 14 = 14