Will works 7 hours a day, 6 days a week.

For one day:
= £9.20 × 7
= £64.40

For six days:
£64.40 × 6 = £386.40

After sharing with his mom:
£386.40/7 × 5
= £55.20 × 5
= £276

To purchase a car worth £1932:
£1932/£276 = 7

Thus, he needs 7 weeks to save enough for the car priced at £1932.