The mean of 20 items is 55. If two items 45 and 30 are removed, what will be the new mean of the remaining items?

If the product of three consecutive numbers is 210 then sum of the smaller number is: 

Running at the speed of 3 km/hr., a person reaches his destination 10 minutes later than usual time. if he increases his speed by 1 km/hr., he reaches his destination 15 min earlier. and the distance to his destination.

A number when divided by 5 leaves a remainder 3. What is the remainder when the square of the same number is divided by 5 ? 

A family has two grandparents, two parents and four children. Two years ago, the average age of grandparents was 72 years. A year ago, the average age of parents was 36 years. Currently, the average age of children is 12 years. What is the current average age of the family?

Simplify the following equation.
$$ {(100)}^{1\over2}.{(0.001)}^{1\over3}-{(0.0016)}^{1\over4}.{3}^{0}+({5\over4})^{-1} $$

A men sells his cycle at 6% profit. Had he sold it at 15% profit, he would have received 180 Rs. More. What is the cost price of the cycle?

If two numbers are each divided by the same divisor, the remainders are respectively 3 and 4. If the sum of the two numbers be divided by the same divisor, the remainder is 2. The divisor is