I need help with this.

sqrt(464)

Step-by-step explanation:

|| 4v|| = || 4* (2i - 5j) ||

         =|| 8i -20j||

We need to find the magnitude

|| 4v|| = sqrt( 8^2 + (-20)^2))

         = sqrt(64+ 400)

         = sqrt(464)

4sqrt(29)

Step-by-step explanation:

||4v|| = 4 ||v||

4 × sqrt[2² + (-5)²]

4 × sqrt(4 + 25l

4 × sqrt(29)

Where,

sqrt: square root

15% chance.

step-by-step explanation:

3/10 times, the 5 year old will get a tablet. 5/10 times, the 13 yer old will get a tablet. multiply both fractions to get 15/100 times, both would have a tablet.