Question

What is the difference in the production of rice in 1969--70 and 1979--80?

• A. 284620
• B. 134790
• C. 149830
• D. 23800

Hint:

“\(\pm d\%\) over previous year” means Current \(=\) Previous \(\times(1\pm d/100)\). To get the previous value, divide by that factor.

Answer 1

The Correct Option is C

From the table:
\(\bullet\) In 70--71, quantity \(=112325\) with \(-16.66\%\) over the previous year (i.e., 69--70). So \(112325 = (1-0.1666\overline{6})\times \text{(69--70)} = \tfrac{5}{6}\times \text{(69--70)}\). Hence \(\text{(69--70)} = 112325\times \tfrac{6}{5} = 134790\).
\(\bullet\) In 80--81, quantity \(=213465\) with \(-25\%\) over the previous year (79--80). So \(213465 = 0.75\times \text{(79--80)}\), hence \(\text{(79--80)}= \tfrac{213465}{0.75}=284620\).
[2mm] Required difference \(=284620-134790=149830\). \[ \boxed{149830} \]