Sue wants to increase 160 by 4%
She writes down
160 1.4 = 224
Sue's method is wrong.
a) Instead of multiplying by 1.4, write down
what she should have multiplied by
0.95
(1)
Bill wants to decrease 160 by 6%
b) Complete the statement below to show how Bill can decrease
| 160 ~
0.06
=

a) To increase 160 by 4% we multiply by 1.04

b) To decrease 160 by 6% we multiply by 0.94

Step-by-step explanation:

a) Here we have to increase 160 by 4% we are to note that;

Therefore, increasing 160 by 4% is to add additional 0.04×160 to 160

That is 160 + 0.04×160 = 160×(1 + 0.04) = 160×1.04

Therefore Sue should have multiplied 160 by 1.04 to increase 160 by 4%.

b) Here to decrease 160 by 6%, we subtract 6% of 160 from 160 that is;

Decrease 160 by 6% = 160 - 160×0.06 = 160×(1 - 0.06) = 160 × 0.94 = 150.4

Hence to decrease 160 by 6% we multiply by 0.94.

the answer is 31.27mph