How old is your sister?
67
67
18 eggs.
1 chicken lays 2 eggs in 3 days, so 3 chickens lay 3×2=6 eggs in 3 days. In 9 days, these 3 chickens lay 3 times as much eggs as in 3 days. Conclusion: three chickens lay 3×6=18 eggs in nine days.
2
The first column totals 9. The second column totals 10. This pattern continues, so the final
column should total 13, by the addition of 2.
The snail reaches the top of the pit on the 16th day!
On the first day, the snail reaches a height of 5 meters and slides down 4 meters at night, and thus ends at a height of 1 meter.
On the second day, he reaches 6 meters, but slides back to 2 meters.
On the third day, he reaches 7 meters, but slides back to 3 meters.
...
Answer is both 1 and 9 whether your using PEMDAS or BODMAS
b) 50
100.
10 + 10 × 10 - 10
= 10 + 100 - 10
= 100
3
There is a 50/50 chance of each toss being either heads or tails. The previous toss does not impact the next toss.
Z = 25.
Y + Y + Y = 120 => 3Y = 120 => Y = 40
X + 40 = 50 => X = 10
10 + Z = 35 => Z = 35 - 10 = 25
4 days
Day 1: 2 -1 = 1
Day 2: 1 +2 -1 = 2
Day 3: 2 + 2 - 1 = 3
Day 4: 3 +2 = 5.
c) 24