at the science school, there is one microscope for every 5 students. The principal figures that in order to have one for every 4 students, she needs 6 additional microscopes. How many students are at the school?

120 students

Explanation:

Let x be the number of scopes
Let a be the number of student at school

1x = 5 students
But 5x = a

1x = 4 students
But the principal needs 6 additional scope so that all the students can use it.

=> (x + 6) = 4 students
=> 4(x + 6) = a

Thus,
5x = 4(x + 6)
5x = 4x + 24
5x - 4x = 24
x = 24

So, there are 24 scopes.

Plug x in both equation and compare:

5x = a
5(24) = a
120 = a

4(x + 6) = a
4(24 + 6) = a
4(30) = a
120 = a

Therefore, the students at the school are 120

Answer: question no. 1 -a. yes, the sides are in the ratio 2 : 5.question no. 2 -b. 59°question no. 3 -c. angles x and y are remote interior angles.question no. 4 -d. 90°, 45° and 45°question no. 5 -b. mn and qrstep-by-step explanation: question no. 1 -rs : xu = 3 : 7.5 = 2 : 5rt : x? = 6.4 : 16 = 2 : 5st : u? = 6 : 15 = 2 : 5as the ratios of all sides are equivalent, the triangles must be congruent and the sides must be proportional.therefore, the answer is: a. yes, the sides are in the ratio 2 : 5.question no. 2 -in the second diagram, angle b is the only letter not shown. therefore, the number must be equivalent to angle b.if we substitute the value of angle b as being 22° in the first diagram, we can now use the angle sum of a triangle to obtain the value of angle a.angle sum of a triangle = 180°therefore: let angle a = aa + 99 + 22 = 180a = 180 - 99 - 22a = 59°therefore, the answer is: b. 59°question no. 3 -angles x and y don't share the vertex of the triangle with the exterior angle w. remote interior angles don't share a vertex of a triangle with an exterior angle. this means that angles x and y are remote interior angles.therefore, the answer is: c. angles x and y are remote interior angles.question no. 4 -the sum of all interior angles of a triangle must be equivalent to 180°.90°, 45° and 45° are the only set of angle measures that are equivalent to 180°.therefore, the answer is: d. 90°, 45° and 45°question no. 5 -the only pair of sides stated in the options which are corresponding are mn and qr.therefore, the answer is: b. mn and qr.