77.49 - 3.99 = 12.25 * x
73.5 = 12.25x
(Divide both sides by 12.25)
6 = x
So, she bought six shirts.
180°. The answer is 180° because it is a straight line rather than being curved/bent.
3)The original rational number was 17/12.
4)The age of Ruby and Reshma are 20 and 28 years respectively.
Explanation:
3)Let the numerator be x.
So denominator will be (x - 5)
If we add 5 to numberator then it will be (x + 5)
New number is (x + 5)/(x - 5)=11/6
Solve for X by cross multiplying
6(x + 5)=11(x - 5)
6x + 30=11x - 55
5x=85
x=17
So original rational number was 17/12.
4)The ages of Ruby and Reshma are in the ratio 5:7
So, let the present ages of Ruby and Reshma be 5x and 7x respectively.
Also, it is given that four years from now the ratio of their ages will be 3:4
So, the equation - 5x + 4 / 7x + 3 = 3/4
⇒4(5x+4)=3(7x+4)
⇒20x+16=21x+12
⇒21x−20x=16−12
⇒x=4
⇒5x=20 and 7x=28
The age of Ruby and Reshma are 20 and 28 years respectively.
To be precise, the size of your sample space is <span><span>(<span>2410</span>)</span><span>(<span>2410</span>)</span></span>. This number does go on the bottom of the fraction, and what goes on top is the size of the event. Break up the event into independent events 1. choose the 2 defective bulbs, and 2. choose the remaining 8 bulbs. I don't have much choice in event 1. There is only one way to choose both of the defective balls. In other words, <span><span>(<span>22</span>)</span><span>(<span>22</span>)</span></span> (choosing 2 defective bulbs from a set of 2 defective bulbs). For event 2, there are <span><span>24−2=22</span><span>24−2=22</span></span> nondefective bulbs, and I must choose <span>88</span> of them, so that's <span><span>(<span>228</span>)</span><span>(<span>228</span>)</span></span>. Finally, since events 1 and 2 are independent, we multiply the answers for the combined event: <span><span><span>(<span>22</span>)</span><span>(<span>228</span>)</span></span><span><span>(<span>22</span>)</span><span>(<span>228</span>)</span></span></span>
<span><span>P=<span><span><span>(<span>22</span>)</span><span>(<span>228</span>)</span></span><span>(<span>2410</span>)</span></span></span><span>P=<span><span><span>(<span>22</span>)</span><span>(<span>228</span>)</span></span><span>(<span>2410</span>)</span></span></span></span>
Or, since <span><span><span>(<span>22</span>)</span>=1</span><span><span>(<span>22</span>)</span>=1</span></span>,
<span><span>P=<span><span>(<span>228</span>)</span><span>(<span>2410</span>)</span></span></span><span>P=<span><span>(<span>228</span>)</span><span>(<span>2410</span>)</span></span></span></span>
Hope this helps!
