A school has 600 pupils. 1/5 are in the upper school, 1⁄4 in the middle school and the remainder in the lower school. How many pupils are in the lower school?

Step-by-step explanation:

the number of pupils are in the lower school

= (1- 1/5 - ¼) × 600

= (20/20 - 4/20 - 5/20)×600

= (11/20) ×600

= 330 pupils

step-by-step explanation:

this is not possible to solve with the info given.   you need at least an one angle somewhere.

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²