HCF and Lcm of two numbers are 7 and 140.If the numbers are between 20 and 45, the numbers are:a.20,49b.35,28c.30,38d.none of these

The answer is b. 35, 28.

Here's the step by step solution:

1. The product of two numbers is equal to the product of their HCF and LCM. So, the numbers we are looking for, let's call them a and b, should satisfy the equation a*b = HCF * LCM = 7 * 140 = 980.

2. Now we need to find two numbers between 20 and 45 that multiply to 980.

3. If we check the options given, we can see that only 35 and 28 satisfy this condition because 35 * 28 = 980.

4. Therefore, the numbers are 35 and 28.