This can be solved by similar triangles, which means you can cross multiply and divide. 78/195=x/10. 78(10)=780 and divide 780 by 195, you'll get the answer is 4. This means Sarah is 4 ft tall.
1 cup is equal to 8 oz, so 3 cups x 8 = 24 oz. you'll do the same for the two cups 2 x 8 = 16 oz so adding them all together will be 24 + 6 + 16 + 9 = 55 total oz.
