Repeated percentage increase and decrease

Maths

Which two decimals would decrease an amount by 10% then increase by 20%?

A decrease of 30%, then an increase of 30%

A decrease of 70%, then a decrease of 30%

A decrease of 70%, then an increase of 30%

An increase of 70%, then a decrease of 30%

What could a multiplication of 0.7 followed by a multiplication of 1.3 represent?

Which two decimals would decrease an amount by 10%, followed by 20%?

A decrease of 30%, then a decrease of 50%

A decrease of 70%, then a decrease of 50%

What could a multiplication of 0.7 followed by a multiplication of 0.5 represent?