Here are the problems:
Mr Greenwill looked out on his Otago farm and saw rabbits everywhere.
“Why”, he said , “I reckon there are about 1280 rabbits in that paddock.
They’ve been doubling in number for the last 7 years.” So how many rabbits were in the paddock 7 years ago?
640 after 1 yr
320 after 2 yr
160 after 3 yr
80 after 4 yr
40 after 5 yr
20 after 6 yr
10 after 7 yr
Henrietta Fowler sells fresh organic eggs every
Saturday morning at the market.
One Saturday morning, she has only 1 egg left,
after serving 8 customers.
Her first customer buys half her eggs
Her second customer buys half the remaining eggs.
Her third customer buys half of what is left.
Her egg sales continue in this way until Egbert, her ninth customer, buys the last egg. No eggs are broken.
1. How many eggs did each customer buy?
2. How many eggs did Henrietta start with? Show your working out.
1. Working Backwards.
9th customer 1
8th customer 2
7th customer 4
6th customer 8
5th customer 16
4th customer 32
3rd customer 64
2th customer 128
1st customer 256
2. Since the first customer bought half the original amount then we need to double 256 so it would be 512.
Congratulations to the McDonnell family for
getting both the questions correct and
showing how they solved it!