If a and b together can complete a piece of work in 15 days and b alone in 20 days, in how many days can a alone complete the work?

If a and b together can complete a piece of work in 15 days and b alone in 20 days, in how many days can a alone complete the work?

The Correct answer is 60

Explanation

(A+B) complete a work in 15 days.

⇒ One day's work of (A+B)=115

B completes the work in 20 days.

⇒ One day's work of B=120

Now, one day's work of A

=1/15−1/20=1/60

Thus, A can complete the work in 60 days.

Multiplication Tables and Patterns

Multiplication tables are a structured way of representing the results of multiplying numbers. They are typically arranged in a grid, with the numbers 1 through 10 (or 12) along the top and left side. The intersection of each row and column in the grid represents the result of multiplying the numbers at the top and left side of that intersection.

Patterns in multiplication tables refer to recurring themes or sequences that can be observed when examining the numbers in the table. For example, in a standard multiplication table, you will notice that the numbers in each row or column increase by a consistent amount. Additionally, certain patterns emerge when looking at the products of specific numbers, such as the multiples of 2, 5, or 10 forming regular patterns.

Understanding these patterns can help with memorizing multiplication facts and developing a deeper understanding of how multiplication works. It can also be useful in solving more complex mathematical problems that involve multiplication.