<PRE><B>Question 995000</B>
Let {{{ a }}} = number of 2 hr classes
Let {{{ b }}} = number of 4 hr classes
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{{{ 2*37 = 74 }}}
{{{ 4*37 = 148 }}}
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(1) {{{ a + b = 41 }}}
(2) {{{ 74a + 148b = 3848 }}}
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Multiply both sides of (1) by {{{ 41 }}}
and subtract (1) from (2)
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(2) {{{ 74a + 148b = 3848 }}}
(1) {{{ -74a - 74b = -3034 }}}
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{{{ 74b = 814 }}}
{{{ b = 11 }}}
and
(1) {{{ a + 11 = 41 }}}
(1) {{{ a = 30 }}}
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30 2 hr classes and
11 4 hr classes were paid for</PRE>