(i) Earning of a labourer in 12 days = Rs 1980
Earning of the labourer in 1 day = 1980 = Rs 165
12
Earning of the labourer in 7 days = 7 × 165 = Rs 1155
(ii) Number of days taken by the labourer to earn Rs 1980 = 12 days
Number of days taken by him to earn Re 1 = 12 days
1980
Number of days taken by him to earn Rs 2640 = 2640 × 12 = 31680 = 16 days
1980 1980