The units digit of (35)^(87) + (93)^(46) is:
For strategies on tough units-digit questions, as well as a complete explanation to this problem, see:http://magoosh.com/gmat/2013/gmat-quant ... questions/
It is quite intuitive to go for a basic two step approach for this problem.
When dealing with 35^87, we can apply a simple concept here. 5 raised to any power > 0 must have 5 as its units digit.
When dealing with 93^46, we can apply the concept of cyclicity. Since the cyclicity of 3 is 4, so units digit of 93^46 is equivalent to teh units digit of 3^2 i.e. 9.
On adding these 2 digits i.e. 9 and 5, we get 14 of which the units digit is 4.
Will be curious to know how others deal with such questions.
Good question, I have the same question in my mind.