The first thing we must do for this case is to define a variable. We have then: x: time it takes the trainee to do the work alone. For this case we have the following equation: 7/21 + 7 / x = 7/12 Solving for x we have: x = 28 hours Answer: it would take the trainee working by herself about: x = 28 hours
712/8=?
First found out what 71/8 is. 71/8 is 8 and 7/8. This tells that there is 7 left so now you add 7 to two which gives you 72. Then you divide 72/8=9 and combine 8 and 9 which gives you 89. So 712/8=89
multiply 3.14 by 2 to the 2nd power by 8. so first 2 to the second power is 4. Then 4x8 is 32. Final step is to multiply 3.14 by 32 to get 100.48. Then you gotta round to get 100.5.