If “*” denotes “added to”, “&” denotes “divided by”, “@” denotes “multiplied by” and “%” denotes “subtracted from”, then
399 & 19 @ 21 % 41 * 100 =?

If “P” denotes “divided by”, “R” denotes “added to”, “S” denotes “subtracted from” and “Q” denotes “multiplied by”, then
48 P 4 R 3 Q 4 S 6 Q 4 = ?

In the following question, by using which mathematical operators will the expression become correct?
30 ? 6 ? 4 ? 5 ? 4

In the following questions, correct the equation by interchanging two signs.
9 × 3 + 8 ÷ 4 – 7= 28

If ‘+’ stands for division, ÷ stands for multiplication, multiplication stands for addition; then which one of the following equation is correct?

In a school, the bell is rung once after each half an hour. The school starts at 8:00 a.m. and closes at 1: 30 p.m. The bell is rung 3 times continuously, at the time of beginning, at the time of lunch break at 10:00 and 10:30 a.m. and at the end. How many times is the bell rung every day? 

Ashok's mother was 3 times as old as Ashok 5 years ago. After 5 years she will be twice as old as Ashok. How old is Ashok today?