Kay must buy approximately 5 bags of potatoes (rounded up) and it would result to $6.975. If possible, she should buy 4.66666667 bags and the cost would be $6.51.
52+10=62
62+10=72
72+10=82
82+4=86
86 is your answer
Let x and y be the rate per hour for Mechanic 1 and 2 respectively.
Then,
x+y=205 ---------- (1)
Additionally,
10x+15y = 2500 ------ (2)
Solving equations 1 and 2;
Multiply (1) by 10 and subtract two from the result,
10x+10y = 2050
10x +15 y =2500
----------------------
-5 y = --450 => y = 450/5 = $90
Then,
x= 205-90 = $115
Therefore,
Mechanic 1 charged $115 per hour
Mechanic 2 charged $90 per hour