Fifteen increased by a number
Answer:
809.4cm²
Step-by-step explanation:
Given the following :
Systematic error = 3.8cm (The measured length is always more than the actual length.)
Most probable dimension :
Width = 85.7 cm
Length = 123.5 cm
Hence most probable area of Rectangle :
Area = Length × Width
Area = 85.7cm × 123.5cm = 10583.95 cm²
Dimension due to Systematic error :
Length = (85.7cm + 3.8cm) = 89.5cm
Width = (123.5cm + 3.8cm) = 127.3cm
Area = Length × width
Area = ( 89.5cm × 127.3) = 11393.35cm²
Systematic error of the area :
value of area with Systematic error - Probable value of area :
11393.35cm² - 10583.95 cm² = 809.4cm²
Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So

1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
m∠A = 40
Step-by-step explanation:
Given AB =AC and m∠B = 70
Since AB =AC , Triangle ABC is an isosceles Triangle and the corresponding angles B and C are equal.
So m∠B = m∠C = 70
The sum of the 3 Angles of a triangle is 180°.
=> m∠A + m∠B + m∠C = 180
=> 140 + m∠C = 180
=> m∠C = 40
Hence the answer is m∠C = 40