1) Yes, both of your scenarios would lead to earning $10 on the transaction, at the strike date. If you purchased both of them (call it Scenario 3), you would make $20.
2) As to why this transaction may not be possible, consider the following:
The Call and Put pricing you describe may not be available. What you have actually created is called 'arbitrage' - 2 identical assets can be bought and sold at different prices, leading to a zero-risk gain for the investor. In the real marketplace, if an option to buy asset X in January cost $90, would an option to sell asset X in January provide $110?
Without adding additional complexity about the features of asset x or the features of the options, buying a Call option is the same as selling a Put option [well, when selling a Put option you don't have the ability to choose whether the option is exercised, meaning buying options has value that selling options does not, but ignore that for a moment]. That means that you have arranged a marketplace where you would buy a Call option for only $90, but the seller of that same option would somehow receive $110.
For added clarity, consider the following: What if, in your example, the future price ended up being $200? Then, you could exercise your call option, buying a share for $90, selling it for $200, making $110 profit. You would not exercise your put option, making your total profit $110. Now consider: What if, in your example, the future price ended up being $10? You would buy for $10, exercise your put option and sell for $110, making a profit of $100. You would not exercise your call option, making your total profit $100. This highlights that if your initial assumptions existed, you would earn money (at least $20, and at most, unlimited based on a skyrocketing price compared to your $90 put option) regardless of the future price. Therefore such a scenario would not exist in the initial pricing of the options.
Now perhaps there is an initial fee involved with the options, where the buyer or seller pays extra money up-front, regardless of the future price. That is a different scenario, and gets into the actual nature of options, where investors will arrange multiple simultaneous transactions in order to limit risk and retain reward within a certain band of future prices.
As pointed out by @Nick R, this fee would be very significant, for a call option which had a price set below the current price. Typically, options are sold 'out of the money' initially, which means that at the current share price (at the time the option is purchased), executing the option would lose you money. If you purchase an 'in the money' option, the transaction cost initially would by higher than any apparent gain you might have by immediately executing the option.
For a more realistic Options example, assume that it costs $15 initially to buy either the Call option, or the Put option. In that case, after buying both options as listed in your scenarios you would earn a profit if the share price exceeded $120 [The $120 sale price less the $90 call option = $30, which is your total fee initially], or dropped below $80 [The $110 Put price less the $80 purchase price = $30]. This type of transaction implies that you expect the price to either swing up, or swing down, but not fall within the band between $80-$120. Perhaps you might do this if there was an upcoming election or other known event, which might be a failure or success, and you think the market has not properly accounted for either scenario in advance.
I will leave further discussion on that topic [arranging options of different prices to create specific bands of profitability / loss] to another answer (or other questions which likely already exist on this site, or in fact, other resources), because it gets more complicated after that point, and is outside the root of your question.