Question 619179
The sum of all the ages of 29 people i.e physicians, surgeons and nurses is 696. 
If the age of each physician, surgeon and nurse be 1 year, 6 year, and 3 years more, then the average age of whole off staff would have been 3 years more.
 If the number of surgeon is a square root of a two digit no. which is also a perfect cube, then the no of nurses in hospital is
:
Let n = number of nurses
Let p = number of physicians
Let s = number of surgeons
;
We should be able to find the number of surgeons from the statement:
"If the number of surgeon is a square root of a two digit no. which is also a perfect cube"
The two digit number would be 64, so we have 8 Surgeons
Therefore nurses and physicians: 29 - 8 = 21
:
s = 8
n + p = 21
:
If the age of each physician, surgeon and nurse be 1 year, 6 year, and 3 years more, then the average age of whole off staff would have been 3 years more.
{{{(1p + 6s + 3n)/29}}} = 3
Replace s with 8, mult equation by 29
p + 6(8) + 3n = 3(29)
p + 48 + 3n = 87
p + 3n = 87 - 49
p + 3n = 39
:
We know p + n = 21, use elimination here
p + 3n = 39
p + n = 21
-------------subtraction eliminates p, find n
2n = 18
n = 9 nurses