During the national day celebrations. asha decorates her balcony with serial lights of red, green and white colours. the red light blinks st intervals of 4 seconds, the green at 5 seconds and the white at 6 seconds. if all three coloured lights blink together at 8: 49 pm, when will they blink together again?

If all three coloured lights blink together at 8:49 pm, they will blink together at 8:50 pm

Solution:

Given that the red light blinks at intervals of 4 seconds, the green at 5 seconds and the white at 6 seconds.

If all three colored lights blink together at 8:49 pm,

We have to find when will they blink together again?

First let us know, at what intervals they all together blink.

For that we have to find the lcm of 4, 5, 6.

L.C.M (4, 5, 6) = 2 x L.C.M(2, 5, 3)

As 2,3,5 are primes, we can’t take common further, so multiply all  

= 2 x 2 x 5 x 3

= 4 x 15  = 60

So, after every 60 seconds = 1 minute they will blink.

Then, after 8 : 49 pm, they will blink at 8 : 49 + 1 = 8 : 50 pm.

Hence, they all blink at 8 : 50 pm.

answer: i wpould go with c

step-by-step explanation:

step by step resolutions

1) n+n+1+n+2=51

3n+3=51

3n=48

n=16

the three numbers are 16, 17 and 18.

2) x+15=4x

3x=15

x=5

radha is now 5 years old

3) the two digits are x and y.

y=3x

(10x+y)+(10y+x)=88

y=3x

11x+11y=88

y=3x

x+y=8

x+3x=8

x=2

the original number can be either 28 or 82.

4) n+(n+2)+(n+4)=48

3n+6=48

3n=42

n=14

the numbers are 14, 16 and 18.

5) y=x+3

10y+x+10x+y=143

y=x+3

11x+11y=143

y=x+3

x+y=13

x+x+3=13

2x=10

x=5

the original number can be 57 or 75.

hope this !