Answer
The BrainBashers electronic word processor has been playing up.
It is replacing every third letter with an a. What should this paragraph read?
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Puzzle 386
What four-digit number has Digit 1 three smaller than Digit 4, which is one more than Digit 2, which is twice Digit 3, which is one more than one third of Digit 4?
Answer
The letter was written on a typewriter which has a problem with the middle row of letters, which print spaces instead. The letter should have read:
Dear Sir,
I recently visited one of your outlets to buy one of your typewriters. However, as you can see I am having a small problem.
The middle row of the keyboard appears to be faulty.
I would be very grateful if you could despatch a replacement by return post. Failing this, could you please send an engineer to resolve this problem as a matter of urgency.
Yours faithfully,
Mrs Middins.
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Puzzle 388
I recently asked a friend of mine to buy me some ribbon for my latest embroidery project.
He went to the haberdashery shop for a particular length, but he accidentally interchanged the feet and inches.
When I measured the purchased ribbon, I only had 30% of the length I required!
Answer
I asked for 9 foot 2 inches (110 inches) and my friend brought me 2 foot 9 inches (33 inches).
Reasoning
I asked my friend to buy me A feet and B inches, which is a total of 12A + B inches.
He accidentally bought me B feet and A inches, which is 12B + A inches.
We know that 12B + A is actually only 30% of what I wanted, so:
12B + A = 0.3 x (12A + B)
Multiply throughout by 10:
120B + 10A = 3 x (12A + B)
120B + 10A = 36A + 3B
117B = 26A
B = 26A ÷ 117
Don't forget that A and B can only be integers, and between 0 and 11.
Since 26 x A has to be at least 117, the lowest possible value for A is 5. We can check the remaining possibilities.
5 x 26 = 130
6 x 26 = 156
7 x 26 = 182
8 x 26 = 208
9 x 26 = 234 (*)
10 x 26 = 260
11 x 26 = 286
The only number wholly divisible by 117 is 234, which means that A = 9, and B = 2.
