if jack can mow his lawn in 4 hours and sue can mow the same lawn in 7 hrs how much time if they both mowed the lawn together???
To find the amount of time it takes for Jack and Sue to mow the lawn together, we can use the concept of work rates.
Let's assign a value to the work rate of each person. Jack's work rate is 1 lawn per 4 hours (since he can mow the entire lawn in 4 hours), and Sue's work rate is 1 lawn per 7 hours.
To determine how long it would take both of them to mow the lawn together, we need to add up their individual work rates.
So, adding Jack and Sue's work rates together gives us a combined work rate of 1/4 + 1/7 lawns per hour.
To simplify this, we need to find a common denominator for 4 and 7, which is 28. The equation now becomes (7/28 + 4/28) lawns per hour, which simplifies to 11/28 lawns per hour.
Now, to calculate the time it would take both of them to mow the lawn together, we can take the reciprocal of their combined work rate. The reciprocal of 11/28 is 28/11.
Therefore, it would take Jack and Sue approximately 28/11 or 2.54 hours (rounded to the nearest hundredth) to mow the lawn together.