Answer:
A
Step-by-step explanation:
6x+3y=33 <=> 2x+y=11<=>4x+2y=22 (1)
4x+y=15 (2)
(1)-(2) <=> y=7
Answer:
C. 45 and 141 seconds
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 93 seconds
Standard deviation = 16 seconds
99.7% of running times are approximately between:
By the Empirical rule, within 3 standard deviations of the mean, so between 3 standard deviations below the mean and 3 standard deviations above the mean
3 stnadard deviations below the mean
93 - 3*16 = 45 seconds
3 standard deviations above the mean
93 + 3*16 = 141 seconds
The correct answer is:
C. 45 and 141 seconds
Answer:
Length of side of rhombus is 
Step-by-step explanation:
Given Rhombus ADEF is inscribed into a triangle ABC so that they share angle A and the vertex E lies on the side BC. We have to find the length of side of rhombus.
It is also given that AB=a and AC=b
Let side of rhombus is x.
In ΔCEF and ΔCBA
∠CEF=∠CBA (∵Corresponding angles)
∠CFE=∠CAB (∵Corresponding angles)
By AA similarity rule, ΔCEF~ΔCBA
∴ their sides are in proportion
⇒ 
⇒ 
⇒ 
⇒
Hence, length of side of rhombus is
Answer:
214°
Step-by-step explanation:
The arc subtending an angle at the centre are equal, that is
arc ED = 90° and
arc DF = 360° - (90 + 146)° = 360° - 236° = 124°
Thus
arc EDF = arc ED + arc DF = 90° + 124° = 214°
