Since 2+8 =10 you would just have 3 left to add so it would be 10+3=13
<span>Because the four numbers are consecutive, we can call the first one x, and the other three are x+1, x+2, and x+3, respectively.
x * (x+1) = (x+2) * (x+3) - 38
x^2 + x = x^2 + 5x +6-38
x^2 + x = x^2 + 5x - 32
-4x = -32
x=8
The four numbers are 8, 9, 10, and 11
check solution: 8*9=10*11-38
72=110-38
72=72</span>
Do you remember when you were learning about
Least Common Multiple (LCM) ? And you were
wondering what on Earth you would ever need it for ?
THIS IS IT !
The amount of time after 8 PM when the lights will flash
together again is the LCM of 20 seconds and 30 seconds.
Do you remember how to find it ?
... When 20 is prime-factored, you have 2 · 2 · 5 .
... When 30 is prime-factored, you have 2 · 3 · 5 .
... So the Least Common Multiple of 20 and 30 is 2 · 2 · 3 · 5 = 60 .
The lighthouses will flash together again in 60 seconds after 8 PM.
That'll be 8:01 PM.
The answer is x = 3.
Hope this helps (:
37 students get at most 67 scores.
The numbers 60-67 represent the lower quartile (lowest 25%). 25% of 60 is 15 not 30. Therefore it is incorrect.
