Ronald has 5 sets of three yellow beads, if there are 2 blue beads for every set, what is the total amount of blue beads?
Let D be Daniel's present age, then we can represent Kevin's present age as 3D because Kevin is 3 times as old as Daniel.
We can write an expression for Daniel's age 4 years ago as D-4 and Kevin's age 4 years ago as 3D-4.
We are told that 4 years ago Kevin was 5 times as old as Daniel. We can write this information as:
Now let us solve our equation to find Daniel's present age.




Daniel's present age is 8 years. Now we will multiply 8 by 3 to get Kevin's present age as Kevin is 3 times old as Daniel.

Therefore, Kevin is 24 years old now.
It will take Dave 7 weeks to earn the right amount of money.
47, 57, 67, 77 are the numbers.
The answer is the option A, which is: A. Equilateral triangles.
The explanation for this answer is shown below:
By definition, a tetrahedron is a solid in three dimensions that has: six sides, four vertices and four triangular faces. These faces are equilateral triangles, which means that all the sides are equal and all the interior angles measure
degrees.
The tetrahedron is also called "triangular pyramid".