Help please?

An altitude of a triangle is a line or segment that passes through a vertex of the triangle and is to the line containing the opposite side.

Galen sold tickets of his church’s carnival for a total of $2,820. children’s tickets cost $3 each and adult tickets cost $5 each. the number of children’s tickets sold was 30 more than 3 times the number of adult tickets slod. how many children’s ticket and how many adult tickets did he sell?

Divide. write in the simplest form. 4 1/6 divided by 10

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?