NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 1: Number System - Multiple Choice Questions

Question 16

Step 1: Find the value of the original expression.

First multiply (-8) and (-3):

Now multiply the result by (-4):

So the original expression equals (-96).

Step 2: Check each option.

(a) (( -8 ) imes ig[( -3 ) imes ( -4 )ig])

Multiply inside the brackets first:

Now multiply by (-8):

This matches the original ((-96)).

(b) (ig[( -8 ) imes ( -4 )ig] imes ( -3 ))

Multiply inside the brackets first:

Now multiply by (-3):

This also matches (-96).

(c) (ig[( -3 ) imes ( -8 )ig] imes ( -4 ))

Multiply inside the brackets first (order doesn’t matter for multiplication):

Now multiply by (-4):

This again matches (-96).

(d) (( -8 ) imes ( -3 ) - ( -8 ) imes ( -4 ))

Here there is a minus sign between the two products, so it is not just regrouping multiplication.

Compute each product:

Now subtract:

(-8) is not equal to (-96).

Conclusion: Options (a), (b), and (c) only change the grouping (associativity) or order (commutativity) of multiplication, so they stay equal to the original value (-96). Option (d) uses subtraction, so its value is (-8), which is different. Therefore, the correct answer is (d).