The answer of question #1 is 48.
To solve this, first you have to solve the (2+1) and that equals 3, now you solve 4(2+1), and that equals 12. Next, you solve the [4(2+1)+3] and that equals 15. Then, you solve {1+[4(2+1)+3} and that equals 16. Lastly, 3{1+[4(2+1)+3} equals 3 times 16=48.
3{1+[4(2+1)+3}=3[1+(4x3+3)]
=3(1+12+3)=3x16=48