1, Assume: the number of shells = x
⇒ [(7x - 7).9] : 2 = 1953
⇔ ( 63x - 63 ) : 2 = 1953
⇔ 63x - 63 = 3906
⇔ 63x = 3969
⇔ x = 63
➤ Answer: 63 shells
2, Assume: the number of flags = y
⇒ [(26y + 132).4] : 10 = 344
⇔ (104y + 528) : 10 = 344
⇔ 104y + 528 = 3440
⇔ 104y = 2912
⇔ y = 28
➤Answer: 28 flags
3, Assume: the number of cartwheels = z
⇒ [(38z - 83).100] : 4 = 19775
⇔ (3800z - 8300) : 4 = 19775
⇔ 3800z - 8300 = 79100
⇔ 3800z = 87400
⇔ z = 23
➤Answer: 23 cartwheels
