Answer:
Step-by-step explanation:
You do not need to where the formula comes from but, just for fun, here’s a hint
To add up the numbers 1 to 10
Write out the numbers
1 2 3 4 5 6 7 8 9 10
Write them backwards
10 9 8 7 6 5 4 3 2 1
Add up both lists
11 11 11 11 11 11 11 11 11 11
This is 10 × 11 = 110
But this is twice the sum as two lots were added together
So the sum of the numbers 1 to 10 is 110 ÷ 2 = 55
ArSeqSum Notes fig4, downloadable IGCSE & GCSE Maths revision notes
3.2+4=7.2
6.6/2.2=3
3+7.2=10.2
10.2
Answer:
5091 Km/hr and 505 km/hr
Step-by-step explanation:
Speed = Distance / Time
Let the speed of first automobile be 'x' and that of the second be 'y'
Since speed of one is 10 times greater than the other. therefore;
⇒ x = 10 y
also let time for faster automobile be 'T' and time for slower auto mobile be 't'
Since first arrive one hour earlier than second, therefore;
⇒ t = T + 1
⇒ For first automobile;
; substituting for 'x' and 'T'. Therefore;
⇒ 
⇒ For Second automobile;
⇒ 
⇒ 
⇒ 5600 +
= 560
⇒ 5600 - 560 = - 
⇒ t = 1.11 hr
also ; T = 1.11 - 1 = 0.11 hr
Speed of 1st auto = 560/0.11 = 5091 km /hr
Speed of 2nd auto = 560/1.11 = 505 km/hr
Answer:
D
Step-by-step explanation:
The formula for the circumference of a circle is 2
r. So if we know that C=60
then we can trace our steps back. We are given that pi remains constant so we are left with the 2r from the formula and a 60. 60/2 =30.
The radius is 30cm