Maths Puzzles

Puzzle: Who Got More?

Mrs Mess was buying a set of garden furniture. The bill was seventy rupees.

She gave the attendant what she thought were two ₹50 notes, (actually two ₹100 notes).

The attendant was sleepy and didn't notice either, so he gave Mrs Mess what he thought were three ₹10 notes (actually three ₹50 notes).

Who ended up better off than they should?
Solution:
Mrs Mess comes away better off than she should, by ₹20 in fact. Despite the warning in the title, Mrs Mess did pay less than she should have done!

Cost of furniture: ₹70

Mrs Mess paid: ₹100 x 2 = ₹200

Change received: ₹50 x 3 = ₹150

Net payment: ₹200 - ₹150 = ₹50

Profit for Mrs Mess: ₹70 - ₹50 = ₹20

Puzzle: Measure exactly 2 litres of water if you have:

1) 4 and 5-litre bowls
2) 4 and 3-litre bowls
Solution . . .
1) Fill the 5-litre bowl; pour water from it to fill the 4-litre bowl, which you empty afterwards.
Pour the remaining 1 litre to the 4-litre bowl.
Refill the 5-litre bowl and then carefully pour water from it to fill the 4-litre bowl (where there is already 1 litre). This will only need 3 litres.
Thus you are left with 2 litres in the 5-litre bowl, as requested.

2) Fill the 3-litre bowl and pour all of the water to the 4-litre bowl.
Refill the 3-litre bowl and fill the 4-litre bowl to the top.
And then you have 2 litres left in the 3-litre bowl.
Puzzle: Bake Sale
Cara, Nick, and Tammy had 96 cookies (8 dozen) to sell at a bake sale.
• Tammy sold 32 cookies.
• Nick sold as many cookies as Tammy sold plus 5 more.
• Cara sold 10 fewer cookies than Tammy sold.
How many cookies did they have left?
Solution
Subtract:
96 the number they had to sell
− 32 the number of cookies Tammy sold
64 the number of cookies left after Tammy sold her cookies
Nick sold 5 more than Tammy. 32 + 5 = 37
64 the number of cookies left after Tammy sold her cookies
− 37 the number of cookies that Nick sold
27 the number of cookies left