A chemical is added to a solution at a rate of milligrams per minute

MATHEMATICS · Single correct · CBSE · Mathematics · Integrals · Integrals

Problem

A chemical is added to a solution at a rate of

r(t)=4t

milligrams per minute. If

30

milligrams have been added between

t=a

and

t=5

minutes (

a<5

), what is the value of

a

? (a)

5-\sqrt{15}

(b)

\sqrt{10}

(c)

2\sqrt{5}

(d)

\sqrt{5}