CAT 1998 — DILR Question 40

Note that one tonne = $\frac{4}{3}$m³ = 1.33 m³,  for both plywood and saw timber.
In 1993, price of logs = Rs. 20 per cubic metre.

Price of plywood = $\left(\frac{7}{1.33}\right)$ = Rs. 5.26 per cubic metre.

And price of saw timber = $\left(\frac{19}{1.33}\right)$ = 14.28 per cubic metre.
Now the sales volume of plywood, saw timber and logs are in the ratio 4 : 3 : 3. So the average realisation per cubic metre of sales is indeed the weighted average.
This is given as $\frac{\left[\right(4\times 5.26)+(3\times 14.28)+(3\times 20\left)\right]}{(4+3+3)}$ = Rs. 12.4

= Rs. 13 (Approximately)