Question 826169
Equation for the teachers and students:
Sum of all their ages = {{{ s[1] }}}
{{{ s[1] / 15 = 17 }}}
{{{ s[1] = 17*15 }}}
{{{ s[1] = 255 }}}
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Equation for the 5 students:
Sum of their ages = {{{ s[2] }}}
{{{ s[2]  / 5 = 14 }}}
{{{ s[2] = 70 }}}
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Equation for the 9 students:
Sum of the ages = {{{ s[3] }}}
{{{ s[3]  / 9 = 16 }}}
{{{ s[3] = 9*16 }}}
{{{ s[3] = 144 }}}
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The teacher's age is {{{ s[1] - ( s[2] + s[3] ) }}}
{{{ s[1] - (s[2] + s[3]) = 255 - ( 70 + 144 ) }}}
{{{ s[1] - (s[2] + s[3]) = 255 - 214 }}}
{{{ s[1] - (s[2] + s[3]) = 41 }}}
The teacher is 41