145%
200/200: 100%
90/200= 45%
B is your answer.
Because 7 times 8 is 56 and 7 times 3 is 21.
If the diameter is 10.5 then the radius is 5.25.
This is because the radius of a diameter is half the diameter.
So
10.5/2
= 5.25
Therefore the radius is 5.25
Given:
In a two-digit number, the tens digit is 5 less than the units digit.
The number itself is five more than three times the sum of its digits.
To find:
The number.
Solution:
Let the two digit number is ab. So,

Tens digit is 5 less than the units digit.
...(i)
The number itself is five more than three times the sum of its digits.



...(ii)
Using (i) and (ii), we get





Putting b=8 in (i), we get


Therefore, the required number is 38.