Mary's hourly wage is twice that of John's. John's and Dennis' hourly wages together total $60. If Dennis earns 1/3 of John's rate, what does Mary make per hour?

Answer: $90

Explanation: This problem can be solved by using following equation : -

Let John's hourly wage rate be J, Mary's hourly wage rate be M and Dennis hourly wage rate be D, therefore : -

Mary's rate will be : -

M = 2J ... equation 1

AND,

J + D = $60 ... equation 2

Similarly,

D = 1/3J

Now, putting the value of D in equation 2 we get,

J + 1/3J = $60

J = $45

Putting the values of J in equation equation 1 we get,

M = 2 * $45

= $90

So, Mary's hourly wage rate is $90