Mary paid $4.20 for 3 candy bars, so each candy bar cost 4.20/3 = $<<4.20/3=1.40>>1.40
Therefore, if Mary buys 7 candy bars, she would spend 1.40*7 = $<<1.40*7=9.80>>9.80. Answer: \boxed{9.80}.
Mary purchases 3 candy bars for $4.20. If she bought 7 candy bars how much would she spend?
1 answer