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

There were 15 persons in a group, they shook hands with each other, then tell how many times the total number of hands were shaken -

If 2 is added to each even digit and 1 is subtracted from each odd digit in the number 621754, then what will be the sum of number/numbers not repeated in the new number?

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

Which two numbers should be interchanged to make the following equation correct?
7 – 8 ÷ 4 + 5 × 3 = 8 × 3 + 6 ÷ 2 – 3

Which two signs should be interchanged to make two given equation correct.
4 × 8 ÷ 16 – 4 + 6 – 3 + 2 = 32

Damini is twice as old as Hari. Hari is 5 years older than Nipa. In 5 years, Damini will be three times as old as Nipa. How old is Hari now?

The ratio of the present ages of Veeru and Sunita is 14:17 respectively. After 6 years from now the ratio of their ages will be 17:20, then what is the present age of Sunita -