Question

M is partly constant and partly varies with N, when N = 14, M = 150 and when N = 54, M = 192.
Find the formula connecting M and N
hence find M when N = 73
solutions
m = k + cn
192 = k + 54c.................... (1)
150 = k + 14c.................... (2)
subtract ( 1 ) from ( 2 )
142 = 40c
divide both sides by 40
142 ÷ 40 = 40c ÷ 40
c = 3.55
put 3.55 for c in ( 1 )
192 = k + 54 × 3.55
192 = k + 191.7
k = 192 - 191.7
k = 0.3
m = k + cn
m = 0.3 + 3.55 × 73
m = 0.3 + 259.15
m = 259.45

Answer 1

Once again 192 - 150 = 42
NOT
142