Question

Stanley's mother owns a stationary shop. Stanley helped his mother pack 319 pencil cases into packets of 7. In the end, 25 packets of pencils cases were sold. How many pencils cases were not sold?​

Answer 1

They sold 25 packets, containing 7 pencils each. So, they sold a total of

`25\cdot 7=175`

pencils. This means that

`319-175=144`

pencils were not sold.