This is meant to be simple, but for some reason I'm not getting the right answer.

Question

Question is: Perhaps the most famous horse race ever in the United States was the 1938 race between two thoroughbreds, War Admiral and Seabiscuit, both of whom stood about 15 hands high. Seabiscuit won the race. The length unit 'hand', used to measure horsesm is exactly 4 inches. How tall are both horses in centimeters.

So I thought:
Convert HANDS --> FEET ---> CM

So 1 hand = 4 in
initial units x desired units/initial units = desired units.

15 hands x 4 in / 1 hand = 60 inches

Seabiscuit is 60 inches tall

1 inch = 2.54 cm

60 inches x 2.54 / 1 in = 152.4 cm

Seabiscuit is 152.4 cm tall.

The answer to this problem in the back of the book is 1.5 x 10^2 cm. I've tried it over and over and it doesn't make sense to me.

Answer 1

I meant
HANDS ---> INCHES --> CM

Answer 2

AHH they are rounding! I feel silly.

Answer 3

15 hands x (4"/hand) x (2.5 cm/1") =152.4 cm.
The number of significant figures may be the problem.
15 hands is two digits; therefore, 152.4 cm would round to 1.5E2 cm.