Take the M60 bus to 125th St. and transfer to the downtown 4 or 5 express train (three stops to 42nd St).
Or, take the Q33 bus to 74th St/Roosevelt Ave. in Jackson Heights and transfer to the Manhattan-bound E or F express train (three stops to Lex./53rd St.)
$1.50 if you use a MetroCard, or $3.00 cash (one fare for the bus and one for the subway).