I am having trouble using a timeline for this problem, could someone please help me with this one

Betty deposits an amount now and withdraws another amount after 9 months. 2 years after the initial deposit her account balance is $7, 096, 529. Bob deposits twice what Betty did, now and withdraws after 15 months 300% of what she withdrew. 2 years after his initial deposit his account balance is $12, 728, 614. If rates are 8% per annum effective then algebraically determine how much Betty deposited and withdrew