i want round 21or 11 or 55 to30 20 60 respectively

To convert the numbers 21, 11, and 55 to 30, 20, and 60 respectively, you need to find the ratio between the original values and the desired values. Then, you can multiply each of the original numbers by this ratio to get the corresponding desired numbers.

Let's calculate the ratio for each number:

For 21 to 30:
Ratio = Desired value / Original value = 30 / 21 = 1.4286

To find the desired value, you multiply the original value by the ratio:
Desired value = Original value * Ratio = 21 * 1.4286 = 30

So, 21 rounds to 30.

For 11 to 20:
Ratio = Desired value / Original value = 20 / 11 = 1.8182

Desired value = Original value * Ratio = 11 * 1.8182 = 20

Therefore, 11 rounds to 20.

For 55 to 60:
Ratio = Desired value / Original value = 60 / 55 = 1.0909

Desired value = Original value * Ratio = 55 * 1.0909 = 60

Thus, 55 rounds to 60.

So, to convert the numbers 21, 11, and 55 to 30, 20, and 60 respectively, you need to multiply each original number by the appropriate ratio as calculated above.