Answer:
hello :
note : 1²+2²+3²+........+n² = n(n+1)(n+2)/6
Step-by-step explanation:
let : S = 1²+2²+3²+......+25²
A = 16²+17²+18²+...+25²
B = 1²+2²+3²+......+15²
S = (1²+2²+3²+....+15²) + (16²+17²+18²+...+25²)
calculate : S for : n = 25
S = 25(26)(27)/6 = 2925
calculate : B for : n = 15
B = 15(16)(17)/6 = 680
so : S = B + A
A = S - B = 2925 - 680 = 2245
Answer: 3 for the first one. and 2 for the second
Answer: the answer is d
Step-by-step explanation:
Answer:
786 feet per min
Step-by-step explanation:
60 (mins in an hour) x 4= 240 mins
there are 5240 feet in a mile
5240 (feet in a mile) x 36= 188640
188640 divided by 240= 768
