First, find 40% of 3,000:
0.40 * 3000 = 1200
So they raised 1200 so far.
Now subtract 1200 from the total they want to raise:
3000 - 1200 = 1800
So they need $1,800 more to meet their goal.
Answer: 56
Step-by-step explanation:
Let's see, if the first one has a Principal of $50, when it doubles the accumulated amount will then be $100,
recall your logarithm rules for an exponential,



now, for the second amount, if the Principal is 500, the accumulated amount is 1000 when doubled,


now, for the last, Principal is 1700, amount is then 3400,
