Which two signs should be interchanged to make the given equation correct? 

306 ÷ 17 + 4 - 50 × 8 = 30

If + means -, ÷ means +, - means ×, and × means ÷ then, what is (80 ÷ 10 - 5) × 4 + 20?

If 'M' means subtraction, 'N' means division, 'O' means addition, and 'P' means multiplication, then which of the following expressions equals 48?

If + means -, ÷ means +, - means ×, and × means ÷ then, what is 20 ÷ 10 - 5 + 15?

If 4 @ 2 = 6 and 5 @ 3 = 8, what is 6 @ 4?

If 6 * 2 = 12 and 3 * 4 = 12, what is 5 * 3?

If

A # B = A² + B,

A @ B = A - B,

A * B = A + 2B,

then what is the value of:

5 # 3 @ 2 * 4?

If 1 = 1, 2 = 4, 3 = 9, then 4 = ?

If % = divided by,
@ = subtracted from,
$ = multiplied by,
& = added to
Then evaluate:
100 % 5 $ 2 @ 10 & 6 =?

At present, the ratio between the ages of Arun and Deepak is 4:3. After 6 years, Arun's age will be 26 years. What is the age of Deepak at present?

A man is engaged for planting trees for 10 hours. He plants 10 trees in an hour. He takes rest for 30 minutes after every hour. How many trees does he plant in 10 hours?

Select the number that will come in the place of the question mark (?), if ‘+’ and ‘-’ are interchanged and ‘x’ and ‘÷’ are interchanged. 

11 × 8 ÷ 5 + 30 − 50 = ?

Which two signs should be interchanged to make the following equation correct? 

139 + 40 ÷ 5 - 168 × 3 = 283