1. **State the problem:** We have an original total cost estimate of 240000 for constructing a house. 25% of this estimate is for labour. Labour cost increases by 50% during construction. Material costs remain the same. We need to find what percentage of the new total estimate is the labour cost. 2. **Identify given values:** Original total cost, $T = 240000$ Labour percentage, $p = 25\% = 0.25$ Labour cost increase, $i = 50\% = 0.5$ 3. **Calculate original labour and material costs:** Original labour cost, $L = p \times T = 0.25 \times 240000 = 60000$ Original material cost, $M = T - L = 240000 - 60000 = 180000$ 4. **Calculate new labour cost after increase:** New labour cost, $L_{new} = L \times (1 + i) = 60000 \times (1 + 0.5) = 60000 \times 1.5 = 90000$ 5. **Calculate new total estimate:** New total cost, $T_{new} = L_{new} + M = 90000 + 180000 = 270000$ 6. **Calculate percentage of new estimate that is labour:** Percentage labour in new estimate, $P_{new} = \frac{L_{new}}{T_{new}} \times 100 = \frac{90000}{270000} \times 100$ 7. **Simplify fraction:** $$ \frac{90000}{270000} = \frac{\cancel{90000} \times 1}{\cancel{90000} \times 3} = \frac{1}{3} $$ 8. **Calculate final percentage:** $$ P_{new} = \frac{1}{3} \times 100 = 33.33\% $$ **Answer:** The labour cost is 33.33% of the new estimate.