2) If Kyle put the whole of it into the 3% account, then she would get 20,000x3%=$600.

For however much she puts into the 5% account, she gets 5-3=2% more.

She got $760 and she gets $600 from the low rate, so she needs $160 more.

If it was all in the high rate account, she would get 20,000x2%=$400 more, but she only wants $160. (Don't know why, though)

This means that she puts 160/400=40% of her money, or $8,000, in the high account.

To summarise, $8,000 at 5% and $12,000 at 3%.

Sorry if I've just made this more complicated with my bad explanation.