Economy size of detergent; 2 kg of detergent cost 3.15=> 1 kg
Costs (3.15/2)
Since 1 kg= 1000 g and 1$=100 cents we have
1000 g of detergent costs ( 3.15/2)* 100 cents or
1 g of detergent costs ( 3.15/2)*100/1000
=3.15/20 cents
Regular size detergent 890 g for 60 thus 1 g costs 60/890 cents
Lets compare 3.15/20 and 60/890
2/43> 3.15/2
The regular size of detergent is more economical