Tim was asked to work out the value of 3 12 = 3 + 33.
His working is shown below, but his answer was incorrect.
On which line did he make his first mistake?
3 x 12 : 3 + 33 = 36 = 3 + 33
Line 1
= 36 = 36
Line 2
=
1
Line 3

1. a music store marks up the instruments it sells by 30%. a. if the store bought a guitar for $45, what will be its store price? b. if the price tag on a trumpet says $104, how much did the store pay for it? c. if the store paid $75 for a clarinet and sold it for $100, did the store mark up the price by 30%?