Solutions by everydaycalculation.com
This multiplication involving fractions can also be rephrased as "What is 40/80 of 10/81?"
4080 × 1081 is 581.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/80×20/81 40/80×30/81 40/80×50/81 40/80×70/81
© everydaycalculation.com