The Gades Foundation and HBM Corporation are eager to donate generously to their favorite charities.

The Gades Foundation donated \$250$250dollar sign, 250 in the first month, and each month afterward their cumulative donation total increases by \$100$100dollar sign, 100.

The HBM Corporation donated \$64$64dollar sign, 64 in the first month, and each month afterward their cumulative donation total increases by 75\%75%75, percent.

They started making donations at the same time, and they both make their monthly donations at the beginning of each month.