please help with a.) and c.) only

1. State the number of significant figures in each of the following measurements. (a) 374; (b) 0.0374; (c) 3074; (d) 0.0030740; (e) 3740 (f) 3.74105; (g) 75 million; (h) 21 thousand; (i) 6 thousandths; (j) 2 hundredths