Some short questions please

1_Which one is correct?
在词典上
在词典里（both are correct）
2_how to say this phrase in Chinese? fix the problem（解决问题（jie3 jue2 wen4 ti2), 问题（wen4 ti2）=problem, 解决（jie3 jue2）=fix）
Northern street(北街，北（bei3）=north, 街（jie1）=street)
3-is this transaction correct?
Sultry weather =潮湿天气(潮湿（chao2 shi1）=humid, Sultry=闷热（men1 re4）,so Sultry weather=闷热天气