Well, darling, 70% of 1500 is 1050. So, if you're looking to calculate that in your head, just move the decimal point one place to the left to find 10%, which is 150, and then multiply by 7 to get 70%. Easy peasy lemon squeezy!
250
70% of 1500 is 1050 when deducted from 1500 is 450
1500
1500
17 / 1500 = 0.01133
15
0.6667
3
(50 / 70) divided by 25 = 2 / 70
0.1349
2.8571