Correct Answer - Option 4 : 1281/441
Given:
A = (3/7) × (9/28) ÷ (81/343)
B = (4/5) ÷ (16/25) + (3/7) × (28/27)
Calculation:
According to the question,
A = (3/7) × (9/28) ÷ (81/343)
⇒ (3/7) × (9/28) × (343/81)
⇒ (3/7) × (1/4) × (49/9)
⇒ (1/4) × (7/3)
⇒ 7/12
Now, B = (4/5) ÷ (16/25) + (3/7) × (28/27)
⇒ (4/5) × (25/16) + 4/9
⇒ (5/4) + (4/9)
⇒ 61/36
Now,
B/A = (61/36)/(7/12)
⇒ (61/36) × (12/7)
⇒ (61/3) × (1/7)
⇒ 61/21
⇒ (61 × 21)/(21 × 21)
⇒ 1281/441
∴ The value of B/A is 1281/441.