Twice a number n is no less than 10 units from −1

the number is n.

the given statement is twice a number n is no less than 10 units from −1.

no less than 10 means either i am 10 or above 10.

  a.t.q

    ⇒ 2 n ≥10-1

⇒2 n ≥9

⇒ n≥9/2

or

2 n≥-10-1

⇒2 n≥-11

⇒n≥-11/2

there is another possibility also

like this

⇒2(- n)   ≥ 10-1 [i have applied negative sign before n because it is not given whether n is positive or negative}

⇒-2 n≥9

⇒2 n≤ -9

⇒n ≤ -9/2

or

2×(-n)≥-10-1

cancelling negative sign from both sides, the equation becomes

⇒2 n≤11

⇒n ≤11/2

so the number is   either n≥9/2 or n≤-9/2.

10.416 m/s

step-by-step explantion:

distance=100m

time= 9.6s

average speed=100/9.6

=10.416 m/s