Respuesta :

Collinzo

Step-by-step explanation:

i = {P×R×T}÷ 100

substitute the terms

78 = (400×R×1.5)÷100

which is 78=6R

divide both sides by the coefficient of R

78\6 = 6R/6

which is 13 = R

so the rate is 13percent

I = interest

p is principal

r is rate

t is time