All right. I will post here some questions related to math and physics mixed. They will go easy to hard, its here so people can know some more.Please also give solutions. First one-
1. I was travelling at speed of 20km/hr and reached my house late by 20min. However I reached my house 15 min. early when I travel at speed of 30 km/hr. By how much time will I be early/late if I travel at speed of 25 km/hr?

Hm. 30-20=10. 10-5=5. So if you cut 10 in half, I would also cut 15 in half which is 7.5 or 7 minutes and 30 seconds. So I would say, you are early by 7 minutes and 30 seconds.

Think again, read question again, see the units(km/hr, min) and see what you are doing is right or wrong.

seems that not much people know about math, so i will reduce the level a bit. heres another one
A and B are rational numbers. what is their value in these equations:
3+J7
____ = A+BJ7
3-J7

J means underroot.

Come up with something simpler next time. Not all are of that age yet to know. xD Proceed.

nobody can do it? anyone?
A and B are rational numbers. what is their value in these equations:
3+J7
____ = A+BJ7
3-J7

J means underroot.

anybody help me out with it!