1. The canteen used 1.6 tons of coal in February, saving 20% compared with 1 month. How many tons of coal are used in January?

Equivalence relation: 1 monthly coal consumption× (1-20%) = February coal consumption.

Equation: x × (1-20%) = 1.6.

x = 1.6 \80 %

X=2

Train speed 106 km, 35% faster than cars. How many kilometers does this car travel per hour?

Equivalence relation: car speed × (1+35%) = train speed.

Equation:

X×( 1+35%)= 106

x = 106 \ 135%

X=78.5