Am I clever enough to work at Google?

Can I answer the job interview questions candidates are asked at Google?

Now, I consider myself to be a reasonably intelligent person. I read a lot. I understand the economic principles behind quantitative easing. I watch University Challenge every week. Sometimes I even answer a few questions, too.

But recently I've begun to doubt my intelligence, and it's all Google's fault.

When Seattle-based interview coach Lewis Lin revealed 10 questions that Google fires at applicants during job interviews, my brain started to throb.

They aren't typically tricky queries like, "What's your main weakness?"

No, these questions are brain-twistingly hard. Some of them take several hours just to read.

But, undaunted, I've decided to tackle them, one by one - and thereby discover whether I'm smart enough to work at Google (not that I want to leave Web User Towers, you understand).

So here we go. . .

1 Why are manhole covers round?
This one I know, but only because I had read it in one of the social psychology books that are so in vogue right now, possibly Malcolm Gladwell's Outliers.

The answer is that if they were square, they could slip down the hole if lifted up. Round ones can't. So I'd be off to a flyer in my fictional job interview.

2 You are shrunk to the height of a nickel and your mass is proportionally reduced so as to maintain your original density. You are then thrown into an empty glass blender. The blades will start moving in 60 seconds. What do you do?

Er, could you repeat the question?

I guess this riddle tests your ability to think "outside the box" (or outside the blender in this case).

Unfortunately, I can't think of anything sensible except maybe headbutt the blender to break it, thus ensuring my escape.

3 How much should you charge to wash all the windows in Seattle?

Surely this depends on what other people already charge, and then decide whether you could afford to undercut them. Would that be the economically literate answer?

4 Explain a database in three sentences to your eight-year-old nephew.

As it happens, in about six months I will have an eight-year-old nephew, so I have a while to prepare an answer for his birthday.

I would probably think of things that he likes, such as Ben 10 toys.

Then explain to him that, instead of leaving all his toys thrown around the bedroom in a heap, he could find them easily if he kept them in a specific order, such as when they were bought, or which are his favourite.

Problem is, he'd get bored in seconds and seek less complex gratification blasting the heads off aliens on his Nintendo Wii.

5 In a country in which people only want boys, every family continues to have children until they have a boy. If they have a girl, they have another child. If they have a boy, they stop. What is the proportion of boys to girls in the country?

Right. Now this requires some serious mental flexing.

The situation must lead to more boys than girls, surely, because there's a 50 per cent chance of either being born, and every time a boy is born, the family stops reproducing - but I guess that's just me repeating the question, and buying myself some more thinking time.

So, 50 per cent of families would stop after the first birth, because they would have a boy.

The remaining 50 per cent of families have a 50 per cent chance of having a boy with every subsequent birth.

Ah, but wait. Having just scribbled down some numbers, I think the answer is that the proportion would be 50/50. The number of families having children would diminish - indeed, halve each birth - but the boy-girl ratio would stay the same.

Wouldn't it?

Am I clever enough to work at Google? Questions 6 to 10