r varies jointly as p and q and r = 30 when p = 5 and q =3

i.Find r when p=8 and q=7
ii.Find p when r =36 and q =2
iii.Find q when r = 40 and p =4​


Sagot :

Answer:

For i, the answer is r = 112

For ii, p = 9

For iii, q = 5

Step-by-step explanation:

Find k;

r = kpq mathematical equation

30 = k(5)(3) substitute the values of r, p and q

30 = 15k divide both sides by 15

2 = k value of k

Find i;

r = kpq mathematical equation

r = 2(8)(7) substitute the given values

r = 112 answer for i

Find ii;

r = kpq mathematical equation

36 = 2(2)p substitute the values

36 = 4p divide both sides by 4

9 = p answer for ii

Last, find iii;

r = kpq mathematical equation

40 = 2(4)q substitute the values

40 = 8q divide both sides by 8

5 = q answer for iii