Question

Jenny washed dishes 4 times as many as her brother last month. Her brother washed dishes 8 times. Jenny said she could multiply 3 times 8 to find how many more times she washed dishes than brother. Is Jenny correct? Explain.

Answer 1

Jenny is incorrect in her calculation.

For every time that Jenny's brother washed dishes, Jenny washed dishes 4 times. This tells that the the times they washed dishes occur in the ratio 4 :1. If Jenny's brother washed dishes 8 times, Jenny has to have washed dishes $4\times 8=32$ times. The way Jenny's is doing the calculation implies that his brother washed dishes $3*\times 8 =24$ times. He calculation yields a wrong result.