John is paid 2 1 2 times his normal hourly rate for each hour he works on a holiday. Last week he worked 45 hours, five hours were on a holiday. Find his normal hourly rate if he earned $420.
Let his normal hourly rate = H
[2.5H * 5] + 40 * H = 420, solve for H
H = $8.00 per hour - his normal hourly rate.