（0.34*2400*0.25+3*7又4分之3+26.25除以3分之1）除以13分之2
=(0.34*600*4*0.25+3*7+3*3/4+26*3+3/4)*13/2
=(204+21+3+78)*13/2
=306*13/2
=153*13
=1989