If i write one digit per second, how long will it take me to write out all the numbers from 1 to 1989? how long : a) 33 min 9 sec b)1 h 22 min 39 sec 3)1 h 54 min d) 1 h 54 min 9 sec e) 2 h 12 min 9 sec i have an exam on sat, average is 1 min 30 sec for each question so i need to know how to do this quickly pleeease.

1 - 9: 9 digits

10 - 99: 90*2 = 180 digits

100 - 999: 900*3 = 2700 digits

1000 - 1989: 990*4 = 3960 digits

This makes 6849 digits or 6849 seconds

D) 1 h 54 min 9 sec

sorry, can't i suggest going to algebra.com

step-by-step explanation:

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.