How many pennies weigh 34 lbs?

Answer 1

This is a trick question - it depends on the pennies' dates, so there's no simple answer.

Pennies made in 1981 and earlier weigh 3.11 gm each. 1983 and later weigh 2.5 gm each. And to get even more confusing, some 1982 cents weigh 3.11 gm and some weigh 2.5 gm!!

If you assume the coins are all relatively new you can use the 2.5 gm figure. A pound is 453.6 gm, so grab your calculator and go from there.