Shortcut Trick
The required numbers are of the form LCM(35, 49) × k + 30, where k is a non-negative integer.
LCM of 35 and 49 is 245.
For k = 0, the number is 30 (not a multiple, but leaves remainder 30 when divided by 35 and 49).
For k = 1, the number is 245 + 30 = 275.
For k = 2, the number is 490 + 30 = 520 (greater than 500).
Therefore, the natural numbers less than 500 are 30 and 275, but since 30 < 35 and 30 < 49, it trivially leaves remainder 30.
Among the standard positive integers satisfying the divisor condition, 30 and 275 are the only two valid values.
∴ The correct answer is 2.
Alternate Method
Let the required natural number be N.
According to the question, when N is divided by 35 and 49, the remainder is 30 in each case.
⇒ N = LCM(35, 49) × k + 30
To find the LCM of 35 and 49:
⇒ 35 = 5 × 7
⇒ 49 = 72
⇒ LCM(35, 49) = 5 × 72 = 5 × 49 = 245
Now, the general form of the number is:
⇒ N = 245 × k + 30, where k = 0, 1, 2, ...
We need to find the number of such natural numbers less than 500:
⇒ For k = 0: N = 245 × 0 + 30 = 30 (Since 30 is a positive integer, it is a natural number)
⇒ For k = 1: N = 245 × 1 + 30 = 275
⇒ For k = 2: N = 245 × 2 + 30 = 520 (which is greater than 500)
Thus, there are exactly 2 such natural numbers: 30 and 275.
∴ The correct answer is 2.
Additional Information
Remainder Theorem & LCM
The smallest number which when divided by x, y, and z leaves a remainder r in each case is given by LCM(x, y, z) + r.
Natural Numbers definition
Natural numbers are positive integers starting from 1, 2, 3, ... etc. Since 30 is positive, it qualifies as a valid natural number under this condition.