Answer:
1.82 gallon or 6.9 litres
Explanation:
Given
Gallon of blue paint= 2 3/5 = (5*2+3)/5 = 13/5 gallon
Fraction of paint used in painting the room = 7/10 of paint available
= 7/10 * 13/5 =91/50 gallon
= 1 41/50 gallon = 1.82 gallon
**converting gallon into litres
one gallon is equal to 3.79 litres
hence 91/50 gallon = 91/50*3.79 litres = 6.9 litres