Class A has 19 pupils and class B has 18 pupils. Both classes sit the same maths test.
The mean score for class A is 77.
The mean score for both classes is 73.
What is the mean score (rounded to 2 DP) in the maths test for class B?

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.

what is the model?

step-by-step explanation: