Question

Which two numbers should be interchanged to make the following equation correct? (28 × 2) -16 ×6+8 × 3+5 × 7 = 39 (Note: Interchange should be done of the entire number and not individual digits of a given number.)

• A. 5 and 3
• B. 8 and 7
• C. 6 and 7
• D. 2 and 3

Answer 1

Answer:

D. 2 and 3

Given:
$(28 \times 2) - 16 \times 6 + 8 \times 3 + 5 \times 7 = 39$

Swap 2 and 3

New expression:
$(28 \times 3) - 16 \times 6 + 8 \times 2 + 5 \times 7$

Now calculate:

• $(28 \times 3 = 84)$

• $(16 \times 6 = 96)$

• $(8 \times 2 = 16)$

• $(5 \times 7 = 35)$

Now:
84 - 96 + 16 + 35
= -12 + 16 + 35
= 4 + 35
= 39

Final Answer: 2 and 3