A) When Sam was calculating a percentage change she multiplied the original value by 1.07.

State whether this was an increase or a decrease and what the percentage change was.

B) when Phil was calculating a percentage change he multiplied the original value by 0.7

State whether this was an increase or a decrease and what the percentage change was

Let us assume x is the increase percentage in decimals, then we need to multiply original value with 1+x.

Similarly if we assume x is the decrease percentage in decimals, then we need to multiply original value with 1-x

A) Given that sam multiplied original value with 1.07 while calculating percentage.

Since 1.07>1, that is an increase.

And percentage change = x*100 = (1.07-1) * 100 = 7 %

B) Given that sam multiplied original value with 0.7 while calculating percentage.

Since 0.7<1, that is an decrease

And decrease percentage = x*100 = (1-0.7) * 100 = 30%