Eli started saving money in his empty piggy bank. He inserted $1 on every Monday, $2 on every Tuesday, $3 on every Wednesday, $4 on every Thursday, $5 on every Friday, $6 on every Saturday, and $7 on every Sunday. At the end of 13 days, he opened his bank and found he had $49. On which day of the week did he start inserting money into his piggy bank?

Guest Jul 16, 2022