Question

In the 1st figure, the left hand side (LHS) and the right hand side (RHS) of the weighing machine are equal to each other. If we add 2 on the RHS, the balance looks like figure 2. What should we do to equalize LHS and RHS again?

• A. Subtract 2 from LHS
• B. Add 5 to RHS
• C. Subtract 5 from RHS
• D. Add 2 to LHS

Answer 1

The correct option is D

Add 2 to LHS

When the weighing machine was balanced, LHS = RHS

⇒ 13x + 5 = 31

New RHS = 31 + 2 = 33

If +2 appears on the RHS of the weighing machine, to balance the machine again, we can add 2 to the LHS of the machine, such that LHS = RHS.
Then LHS = (13x + 5) + 2 = 13x + 7

Let us see what happens.

The machine is balanced again.