100 gives PRT
The simple interest formula I
the interest I on a principal P invested at a
rate of R% per annum for T years.
a Find the interest when N150 000 is
invested at 5% per annum for 4 years.
b Find the principal that gains an interest of
N16100 in 5 years at 7% per annum.

Step-by-step explanation:

a. Given,

Principal ( P ) = N 150000

Rate ( R ) = 5 %

Time ( T ) = 4 years

Interest ( I ) = ?

Finding the Interest ( I )

⇒

⇒

⇒

Interest = N 30000

------------------------------------------------------------

b. Given,

Interest ( I ) = N 16100

Time ( T ) = 5 years

Rate ( R ) = 7 %

Principal ( P ) = ?

Finding the principal

⇒

⇒

⇒N

Principal = N 46000

Hope I helped!

Best regards!!

Step-by-step explanation:

a) P = N 150000

R = 5%

T = 5 years

Plug in the values P,R & T in the  formula

I = PRT

I = N 30000

b) I = N 16100

R = 7%

T = 5 years

P= N 46000

The warranty period should be of 35 months.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean and standard deviation , the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Cook-Easy blender has a mean time before failure of 41 months with a standard deviation of 4 months

This means that

What should be the warranty period, in months, so that the manufacturer will not have more than 8% of the blenders returned?

The warranty period should be the 8th percentile, which is X when Z has a p-value of 0.08, so X when Z = -1.405.

Rounding to the nearest integer, 35.

The warranty period should be of 35 months.