Question

Convert: 15 English tons (short) to metric tons.

Answer 1

90.72 x 15 = 1,360.8

13.6

Answer 2

A metric ton is a million grams, 1 megagram or 1 Mg.

1 lb = 0.00045359237 Mg . . . . conversion factor (exact)
2000 lb = .90718474 Mg . . . . . multiply the above equation by 2000
1 short ton = 0.90718474 Mg . . . recognize 2000 lb = 1 short ton

Now, this equation can be multiplied by 15 to get your conversion.
15 short tons = 13.6077711 Mg