The obvious one is (310 beats)/(1 minute).
Yea, there's a formula :
radians = degrees × π / 180°
Answer:
5 cm
Step-by-step explanation:
We khow that the altitude of this triangle is 1cm shorter than the base
- Let H be our altitude and B our base and A the area of the triangle
- A= (B*H)/2 ⇒ 15=(B*H)/2
- H is 1cm shorter than B ⇒ B=H+1
- H*(H+1)/2=15 ⇒ H*(H+1)=30⇒ H²+H=30⇒H²+H-30+0
that's a quadratic equation . Let's calculate the dicriminant .
Let Δ be the dicriminant
- a=1
- b=1
- c= -30
- Δ=b²-4*a*c = 1²-4*1*(-30)=1+4*30=121≥0
- Δ≥0⇔ that we have two solutions x and y
- x= (-1-
)/2= (-1-11)/2= -6 - y= (-1+
)/2= 10/2 = 5
We have a negative value and a positive one
The altitude is a distance so it can't be negative
H= 5cm
Answer:
216 boys
Step-by-step explanation:
450 students: 20% girls, 80% boys
450*20%=90 girls
450*80%=360 boys
Students having mobile phones: 40% (OF THE 90) girls, 60% (OF THE 360) boys
90*40%=36 girls
360*60%=216 boys
[We honestly don't need to care about the girls without mobile phones as they are only asking how many boys have mobile phones]